HIGH ALTITUDE VEHICULAR EMISSION CONTROL PROGRAM
VOLUME VIII. PILOT TRAINING PROGRAM
RESULTS FOR MOTOR VEHICLE
EMISSION CONTROL
SUPPLEMENT
Prepared for
Stat* of Colorado
Department of Health
Denver, Colorado 80220
cTu
Environmental Protection Agency
Region VIII
Denver, Colorado 80203
Colorado
State
-------
U \ C\lv «^VU^nrnjuoU^d^
V)^'
\((^L YUJ Q20l
FINAL REPORT ON COLORADO MOTOR VEHICLE
EMISSION CONTROL EDUCATIONAL
TRAINING PROGRAM
Submitted to
State of Colorado
Department of Health
By
Department of Industrial Sciences
Colorado State University
Fort Collins, Colorado
-------
DISCLAIMER
This report has been financed in part with State funds
from the State of Colorado Department of Health, Denver,
Colorado 80220 and prepared by the Industrial Sciences
Department at Colorado State University under Contract/
Grant Number C291146.
The conclusions, opinions, and findings are those of
the project team members and are not necessarily those
of the Colorado State Health Department. Mention of
company or commercial product names does not constitute
endorsement by the project team members, the State Health
Department, or Colorado State University.
The results and conclusions presented are based on data
gathered by the Industrial Sciences Department of Colorado
State University.
The limited number of people involved in the pilot programs
could have significant impact, on the conclusions and
recommendations.
-------
TABLE OF CONTENTS
Chapter Page
1.0 CONCLUSIONS AND RECOMMENDATIONS 1
2.0 PROJECT OBJECTIVES 4
3.0 INTRODUCTION 6
Purpose of the Project 8
Method and Procedure 9
Pilot Training Program 11
Colorado State Automotive Teachers
Workshop 13
4.0 SUMMARY OF VEHICLE EMISSION CONTROL
TEACHER TRAINING PROGRAM AND PROJECT
ACTIVITIES 15
Instructional Material Development 17
Evaluation of Materials 18
Winter and Spring Emission Classes 19
Follow-Up Visitation/Survey 21
Development of Proposed Criteria For
Investigators and Inspectors 26
Public-Information 33
5.0 ANALYSIS OF TEST RESULTS 34
Appendixes
A. MOTOR VEHICLE EMISSION CONTROL
DELIVERY SYSTEM MODEL 42
B. FORTY-HOUR COLORADO TEACHER
TRAINING COURSE OUTLINE 44
• * •
-------
51
63
76
79
95
108
172
189
192
197
202
218
223
233
239
248
250
258
MOTOR VEHICLE EMISSION CONTROL
REFERENCE MATERIALS
MOTOR VEHICLE EMISSION CONTROL
LABORATORY WORKSHEETS
PROJECT ASSUMPTIONS
MOTOR VEHICLE EMISSION CONTROL
CURRICULA OUTLINE
MOTOR VEHICLE EMISSION CONTROL
BEHAVIORAL OBJECTIVES
MOTOR VEHICLE EMISSION CONTROL
SLIDE NARRATIONS
MOTOR VEHICLE EMISSION CONTROL
TEST QUESTIONS
MOTOR VEHICLE EMISSION CONTROL
SUPPLEMENTARY REFERENCE MATERIALS
MOTOR VEHICLE EMISSION CONTROL
WORKSHOP EQUIPMENT
MOTOR VEHICLE EMISSION CONTROL
NONDISPERSIVE INFRARED ANALYZER NARRATIVE
MOTOR VEHICLE EMISSION CONTROL
CHEMISTRY OF THE INTERNAL COMBUSTION
ENGINE NARRATIVE
SLIDE AND NARRATION EVALUATION FORMS
EMISSIONS I AND II COURSE OUTLINE
FOR AUTOMOTIVE INSTRUCTORS
PRE-TEST: IGNITION AND CARBURETION
AUTOMOTIVE TEACHERS' EMISSION EXAMINATION
COLORADO AUTOMOTIVE TEACHER QUESTIONNAIRE
MOTOR VEHICLE EMISSION CONTROL
PRE/POST-TEST
PROPOSED CRITERIA, QUALIFICATIONS, AND
PROCEDURES FOR INSPECTORS AND STATE
INVESTIGATORS CERTIFICATION
-------
LIST OF TABLES
Table Page
I Location and Number of Colorado
Teachers Surveyed 22
II Emissions Classes Conducted by
Colorado Teachers 24
III Planned Emissions Classes by
Colorado Teachers 25
IV Estimated Instruction Cost for
Investigator and Inspector Training . . 30
V Estimated Instruction Cost ($) Per
Student for Inspector Training 31
VI Estimated Instruction Cost ($) Per
Student for Investigator Training ... 32
VII Teacher Pre-Test Results 36
VIII Information on Teachers Concerning Age,
Mechanic and Teaching Experience. ... 36
IX College Student Pre-Test Results. ... 37
X Ignition/Carburetion Pre-Test Results . 38
XI Teacher Post-Test Results 39
XII College Students Post-Test Results. . . 40
XIII Comparison of Pre and Post Test Results 40
XIV Results of Teacher Emission Test. ... 41
-------
1.0 CONCLUSIONS AND RECOMMENDATIONS
The conclusions and recommendations presented herein are derived
from the Colorado Motor Vehicle Emissions Control Educational
Training Program and activities conducted by the Industrial
Sciences Department at Colorado State University.
Conclusions
(1) The instructional materials and evaluation instru-
ments developed during the project and evaluated
by automotive teachers have proven to be satis-
factory for use in emission control systems training.
(2) Twenty-six (26) automotive teachers in the DAQCR
benefited from the forty (4 0)-hour emissions
control training program conducted by Colorado
State University.
(3) An effective vehicle emissions control training
program can be disseminated by properly trained
automotive instructors to the automotive service
industry.
(4) Consultant services to emissions control teachers
in the field was a minor aspect of the project;
however, consultant services will-have a greater
impact on future training.
-------
2
(5) The suggested certification requirements developed
for inspectors and investigators will insure the
integrity of an emission inspection/maintenance
program.
Recommendations
(1) Revisions and additions to developed instructional
materials must be continued to maintain a relevant
training program.
(2) In-service, up-dated training for those DAQCR
teachers who previously attended Colorado State
University emission control workshops should be
provided.
(3) Provide instruction to those automotive teachers
desiring to become qualified to train repairmen,
inspectors, and investigators.
(4) Provide training to approximately 1,000 mechanics
in the DAQCR to qualify them as emission control
repairmen and inspectors. Emphasis should be
placed on inspection and diagnostic procedures,
and the proper use of testing equipment during the
training.
(5) Establish an emission control certification and
training center for repairmen, inspectors, and
-------
3
(6) The training center personnel should act as
disseminators of public information, and as emission
control consultants to teachers, repairmen, inspec-
-------
2.0 PROJECT OBJECTIVES
The primary objectives of the project were to:
(1) develop educational instructional material
for emissions control teachers.
(2) develop evaluation instruments for emissions
control teachers.
(3) conduct a forty (40)-hour emissions control
workshop for twenty-five (25) automotive teachers
within the Denver Air Quality Control Region.
(4) develop Colorado Motor Vehicle Emissions Control
certification requirements.
(5) provide consultant services to emissions control
teachers in the field.
(6) provide and administer instruments in evaluating
instructional materials used in pilot program
for automotive teachers.
(7) provide course outlines on training program
for motor vehicle emissions control to be used
by teachers in the field.
(8) provide written recommendations on techniques
to be used in implementing an effective certi-
fication and educational program on motor vehicle
emissions control.
-------
5
(9) provide monthly progress reports on project.
(10) provide interim report by February 15, 197 5,
with tentative recommendations on certification
program for inspectors, investigators, repairmen
and automotive teachers.
(11) provide final report with revised recommendations
-------
3.0 INTRODUCTION
This is the final report on the Colorado Motor Vehicle
Emissions Control Educational Training Program. The
project is focused toward: providing an educational
program for twenty-five C25) motor vehicle emission control
teacher educators; developing certification requirements
for emission control inspectors and investigators; providing
course outlines and evaluation instruments to be used by
prospective emission control teachers; and evaluating
instructional materials developed for the training of
automotive teachers. This project developed 240 - 35mm
slides and the same number of matching transparencies with
narrations portraying five (5) vehicle emission control
systems used by various automotive manufacturers. In
addition to the slide series, a video tape program was
produced illustrating the chemistry of the internal com-
bustion engine and its related pollutants; namely, hydro-
carbons, carbon monoxide and oxides of nitrogen.
The project provides the necessary instructional, training
and evaluation materials for a delivery system to be
administered to auto mechanic teachers and other people
in the automotive inspection, maintenance and repair
industry. In developing the vehicle emission control
-------
7
teacher training program, the following assumptions were
considered:
(1) Instructional materials are designed for
teacher use.
(2) Teachers will be familiar with carburetion,
electrical, and engine theory.
(3) Teachers will be familiar with emission systems.
(4) Teachers will be familiar with electrical test
equipment.
(5) Teachers will be familiar with diagnostic
procedures.
(6) Teachers will be familiar with the effective
use of instructional media.
(7) All teachers will have trade experience.
In fulfilling the requirements of the contract, with the
Colorado State Department of Health, the Department of
Industrial Sciences at Colorado State University conducted
two (2) emissions control workshops for twenty-six (26)
automotive teachers.
In addition to the teacher training workshops, a pilot
course in automotive emissions was conducted for eleven (11)
graduate and undergraduate students on campus at Colorado
State University by the Department of Industrial Sciences.
-------
8
that offered to the twenty-six (26) instructors.
Purpose of the Project
The overall purpose of this project was to develop instruc-
tional materials for an effectiyedeliverysystem concerning
the orientation and maintenance on motor vehicle emission
control systems for automotive teachers, and to establish
inspection certification requirements for inspectors and state
investigators to effectively implement a program.
The engineering changes on automobile emission control devices
are becoming more complex every day. Compounding this
situation is the apparent and distinct lack of instruc-
tional materials designed to aid the automotive teacher
in the task of teaching vehicle emission control systems.
With the introduction of the catalytic converter, warm-
up systems, electronic ignition, carburetor modifications,
and emphasis on fuel economy, changes in our teaching
materials and methods are needed. The situation was recog-
nized and upheld further by the Air Pollution Control
Commission's report to the Governor in 1973. The commission
concluded that inadequate training opportunities and skills
presently exist; one of the key elements of an effective
vehicle emission inspection program is the proper training
of inspectors and investigators. To comply with these
-------
9
Industrial Sciences at Colorado State University was
awarded a contract by the Colorado State Department of
Health for developing a training program and necessary
instructional material on motor vehicle emission control
systems. Under the same contract, Colorado State University
developed certification requirements and procedures for
emission control inspectors and state investigators.
Method and Procedure
In order to implement an effective and efficient Colorado
Motor Vehicle Emission Control Educational Training Program,
it was essential to develop a delivery system consisting
of the appropriate components and adequate instructional
materials and personnel. To fulfill such a requirement,
the Department of Industrial Sciences at Colorado State
University, with support and guidance from the Colorado
State Departments of Health and Revenue, Colorado
State Board of Community Colleges and Occupational
Education, Vocational-Technical Training Institutions in
Colorado,. Department of Vocational Education at Colorado
State University and other supporting facilities, including
the Media Center at Colorado State University, proposed
the establishment of a delivery system model for an
instructional program on vehicle emission controls (see
-------
10
concentrated on the initiation and implementation of
a vehicle emission control training program for
Colorado's automotive instructors that would assist
in advancing the state of the art in mobile air
pollution abatement.
The project was directed toward:
(1) analyzing information, materials and results
of various field tests now being performed
by private, state and other agencies on
vehicle emission control.
(2) selecting twenty-five (25) qualified automotive
teachers in the vocational and technical
institutions from the Denver Air Quality Control
Region to participate in the Colorado Motor
Vehicle Emission Control Educational Training
Program conducted by Colorado State University.
(3) providing selected teachers in Colorado with
the appropriate educational and training
background on motor vehicle emission control.
(4) providing adequate instructional materials to
selected automotive teachers so they may provide
instruction for inspectors, investigators,
repairmen, and vocational and technical
students throughout the state.
-------
11
teachers and inspectors on instructional and
course materials as they were being developed.
(6) developing evaluation methods for vehicle
emission training programs, follow-ups, and
recommendation of the results.
(7) develop criteria and procedures for the certi-
fication of inspectors and investigators in
Colorado.
Pilot Training Program
Three years ago, an emissions control training program in
Colorado began with the instruction of one hundred fourteen
(114) veteran mechanics on automotive emission control
theory, maintenance, and service. The classes were con-
ducted for Region VIII of the Environmental Protection
Agency by the Industrial Sciences Department at Colorado
State University. The program consisted of thirty-two (32)
hours of classroom instruction and one hundred twenty-eight
(128) hours on-the-job training in the use of exhaust
analyzers and diagnostic test equipment.
Another pilot training program on motor vehicle emissions
control was developed and implemented by the Industrial
Sciences Department at Colorado State University for the
Department of Health and Revenue. The training program
-------
12
inspectors and six (6) state investigators.
The following procedures were employed in the development,
teaching, and evaluation of the pilot program:
(1) Reviewed service and maintenance requirements for
the motor vehicle emissions control for state
investigators, inspectors, and repairmen.
(2) Reviewed "State of the Art" in Colorado con-
cerning service stations, equipment, and personnel
as it relates to vehicle emissions control.
(3) Reviewed data collected by Automotive Testing
Laboratories, Inc., concerning the field test
of idle test emissions on randomly selected
automobiles.
(4) Reviewed instructional materials now available
concerning motor vehicle emissions control.
(5) Compiled results of these reviews and analyzed
the implications for needed instructional
materials and programs on motor vehicle emissions
control.
(6) Compiled and developed instructional materials
to be used in conducting pilot training programs
for state investigators and inspectors.
(7) Conducted pilot training programs for six (6)
state investigators and fifteen (15) inspectors.
-------
13
(9) Revised instructional program as needed in terms
of findings from pilot programs.
The pilot training programs conducted by Colorado State
University for evaluating the training needs for auto-
motive emission control personnel indicated the following:
1) more than six (6) hours of instruction are needed to
provide adequate information for investigators and inspectors;
2) state regulatory laws and guidelines are needed to
give guidance to the automotive emissions program; 3) a
certification program is needed to insure the proficiency of
the inspector and investigator; 4) test sites and equipment
will be needed to train inspectors and investigators.
Colorado State Automotive Teachers Workshop
In June, 1974, Colorado State University instituted a one-
week, forty (40)-hour automotive emissions workshop for twenty
Colorado vocational automotive teachers. This instructional
program was conducted on the campus of Colorado State
University. The results and recommendations obtained from
the mechanics and inspector/investigators pilot training
program were used as the basis for developing the forty (40)-
hour teacher workshop trianing course. The principle
objectives of this workshop were: 1) to provide instruc-
tion on the orientation and basic maintenance procedures
-------
14
evaluate course material and laboratory activities to be
administered in future emission control workshops. As a
result of the Colorado State one-week workshop, existing
instructional materials were gathered and evaluated.
Further additions and revisions of these materials were
made and implemented during the National Automotive Teachers
Workshop held in July on the Colorado State University
-------
4.0 SUMMARY OF VEHICLE EMISSION CONTROL TEACHER
TRAINING PROGRAM AND PROJECT ACTIVITIES
In partial fulfillment of the contract with the Colorado
Department of Health, Colorado State University was to
provide emission control training for twenty-five (25)
Colorado automotive teachers. In conjunction with this
objective, instructional materials were to be developed
for use by automotive teachers to conduct emission
control training.
Utilizing the training materials used for previous pilot
programs, revisions and new materials developed by the
twenty-three (23) participants in the National Automotive
Workshop, an outline was developed for the forty (40)-hour
Colorado teacher training program (see appendix B). This
forty (4 0)-hour training class was scheduled from August
19 through August 23 at the Warren Occupational Technical
Center in Denver.
Letters with applications were mailed to approximately
sixty (60) Colorado automotive teachers, primarily in
the Denver Air Quality Control Region. Because the
training program coincided so closely with the opening
-------
16
of many schools, only eleven (11) teachers responded;
however, four (4) service personnel from industry requested
and were given permission to attend the class.
The instructional materials selected for the classroom
texts were: Emissions Control Manual by Gargano, Vehicle
Emissions Control by Motorcraft, and Emission Control
Systems Maintenance Manual by General Motors. The Mitchell
Manual's Automotive Emission Control Service Manuals were
used as the reference and technical books for the laboratory
exercises. Additional reference materials, supplementing
the classroom texts, were primarily filmstrips from Mitchell
Manuals and Gargano along with video tapes from General
Motors, Ethyl Corporation and Ford Motor Company (see
appendix C).
The workshop activities were divided into approximately four
(4) hours of class lecture and four (4) hours of laboratory
experiences with hands-on exercises related to classroom
instruction. Six laboratory worksheets were used for
the hands-on assignments (see appendix D). The fifteen (15)
participants were divided into five teams of three members
each. Five vehicles were procured from local automotive
dealerships allowing each team a vehicle on which to work.
During the laboratory period the participants became
-------
17
equipment and infrared analyzers. Instruction and demonstra-
tions stressed that proper diagnostic procedures on emission
controlled vehicles were more important than on pre-controlled
vehicles.
At the conclusion of the training, the majority of the
participants expressed a willingness to become involved
in training other personnel. The automotive teachers
felt that future refresher training would be necessary to
maintain an effective Vehicle Emission Control training program.
Instructional Material Development
Development of a training program for automotive teachers
covering five vehicle emission control systems was initiated
by the National Automotive workshop participants in July,
1974. The emission control systems researched and
developed were: air injection reaction, exhaust gas
recirculation, fuel evaporation, positive crankcase ventila-
tion, and thermostatic air control. From the initial assem-
bly of the training program, incorporating the five emission
systems, the project staff further developed and refined
this material. The services of the Colorado State University
Media Center were enlisted to provide the professional
graphic expertise needed to produce the visual aids.
These aids consisted of 240 - 35mm slides with matching
-------
18
on the "Nondispersive Infrared Analyzer" and "Chemistry
of the Internal Combustion Engine". This collective effort
by the National and State project staff and Media Center,
in cooperation with workshop participants resulted in the
development of an emissions instructional materials packet.
This packet contains assumptions, supplementary reference
materials, equipment list, curricula outline, laboratory
worksheets previously discussed, emission reference materials,
behavioral objectives, 35mm slide narrations, test questions
pertaining to each emissions system and the narrations
for the two video tapes mentioned previously (see appendixes
D, E, F, G, H, I, J, K, L, M).
Evaluation of Materials
Upon the completion of the training materials eighteen (18)
Colorado teachers who had previously attended emission
control workshops were each given a set of these training
aids. These teachers, their students, and teachers who
participated in the National workshop, evaluated the
materials on forms developed by the project team (see
appendix n). In addition to the evaluation sheets for the
slides and narrations, evaluations were requested on the
objectives, test questions, and laboratory worksheets.
As the evaluations were returned, the necessary changes
and adjustments were made to the instructional materials
-------
19
Winter and Spring Emission Classes
During the Fall Quarter, 1974, several students at Colorado
State University indicated a strong interest in vehicle emission
control training. To comply with an administrative decision
the existing emissions training program was divided into Emissions
I and Emissions II, offered Winter and Spring Quarters respec-
tively, as part of the regular Industrial Sciences curriculum.
Emissions I was primarily classroom instruction devoted to
theory, purpose, diagnosis, operation of emission control
systems, carburetion, and ignition systems. The Emissions
II class was designed to offer the students hands-on laboratory
experience directly related to emission control systems and
diagnostic procedures. Each class offered approximately fifty
(50) hours of instruction. This met the universities require-
ment regarding contact hours necessary to earn the designated
college credit. Because of the low teacher enrollment in the
summer workshop at the Warren Occupational Technical Center, it
was decided to offer the emissions class off campus to Denver
area automotive teachers. This allowed many of the automotive
teachers the opportunity to take a class in vehicle emission
controls they were unable to attend during the summer.
Richard Zimpel, from the State Vocational Department,
offered his services by notifying the Denver area vocational
-------
20
Graduate credit was made available to those desiring it.
The class enrollment at Red Rocks Campus and Colorado
State University was fifteen (15) and eleven (11)
respectively.
An instructor, Gary Dugan, was hired and approval to use
the Community College of Denver Red Rocks auto facility
was obtained for the off-campus course. The project staff
and Mr. Dugan met and revised the curricula outline (see
appendix 0) and ordered the necessary instructional materials
(see appendix J). A unit on electronic ignition was included
in the course since it is standard equipment on most 1975
vehicles and is an integral part of emissions control.
With the addition of electronic ignition to the course
it became imperative that components, manuals and visual
aids be procured for instruction. Manufacturers, dealers
and training centers were contacted to obtain the necessary
aforementioned items. Pre-tests covering general mechanical
knowledge, emissions, carburetion and ignition were revised
and written for the students in order to establish a
basis of what areas in the course needed the most concentra-
tion (see appendix P).
During the Spring Quarter classes three automotive instructors
-------
21
automotive instructors. The purpose of the examination
is to provide an evaluation tool in determining the knowl-
edge an individual possesses about vehicle emission
control systems. After assembly the test was administered
to the automotive teachers enrolled in the Emissions II
class at Red Rocks Campus. As the teachers took the
test they were asked to evaluate the questions and submit
written comments as to changes, additions and deletions
that needed to be made. A copy of the revised examination
can be found in appendix Q.
Follow-Up Visitation/Survey
In April a follow-up survey was conducted by the project
director. Five days were spent making personal contact
with eighteen (18) Colorado automotive teachers selected
by the emissions staff. All of the teachers had attended
one of the emissions training workshops conducted by
Colorado State University during the Summer of 1974. Table I
shows the location, type of school and the number of instructors
contacted in the particular city or town.
The principal purpose of the follow-up was to gather information
on the progress Colorado teachers had made on conducting
emission control training classes in their particular area.
In order for the delivery model (see appendix A) to be effective
-------
22
Table I
Location and Number of Colorado Teachers Surveyed
Location
Number of Instructors
in location
Type of School
Grand Junction
1
College
Glenwood Springs
1
Voc. Center
Cortez
1
Voc. Center
La Jara
1
High School
Salida
1
High School
Pueblo
1
College
Colorado Springs
2
Community College
Denver
5
High School
Boulder
1
Voc. Center
Greeley
1
College
Fort Collins
1
Voc. Center
Lamar
1
Community College
Fort Morgan
1
-------
23
similar information and training to teachers, students and
repairmen in their local. The goal of the program was
to prepare personnel that are qualified to inspect and maintain
emission controlled vehicles in accordance with the development
of a state emission inspection/maintenance program.
Prior to conducting the survey a questionnaire was developed
(see appendix r). This form was completed on each of the
instructors when they were contacted. The results from the
questionnaire related to emission classes conducted are
compiled in Table II. As shown in the table, most of the
instructors integrated emissions training into their regular
automotive curriculum. The following results are the number
of students, by type, who received emissions training:
High School -------------- 584
Post Secondary- ------------ 58
College ---------------- 20
Mechanics --------------- 58
Table III reveals data pertaining to future emissions training
classes to be conducted by the eighteen (18) instructors.
Identified in the table are the number of classes, dates,
length of classes in hours, type of students and assistance
requested by the individual teachers. Indicated by the last
column in Table III a majority of the instructors expressed
-------
1
2
3
4
5
6
7
8
9
9
10
11
12
13
14
15
16
17
18
Location
Table II
Emissions Classes Conducted By Colorado Teachers
Sections or Length of work- # of # of
# of workshops
held
shop/section
(Hrs.)
Separate
Sections
Integrated
Sections
Type of
Partici-
pants
# of
partici-
pants
Post. Sec.
38
Mech.
22
H.S.
26
H.S. & P.S.
24
P.S.
20
H.S.
100
H.S.
28
Mechanic
14
H.S. & P.S.
48
Mech.
12
H.S.
50
H.S.
33
H.S.
59
H.S.
10
Mech.
10
College
20
H.S.
14
H.S.
45
H.S.
30
H.S.
32
H.S.
85
Ft. Collins
Salida
Lamar
Aurora
Colo. Springs
Greeley
Grand Junct.
Colo. Springs
Ft. Morgan
Denver
Cortez
Pueblo
Denver
La Jara
Boulder
Denver
Denver
Glenwood
3
3
1
1
1
4
1
1
1
0
4
1
8
1
1
1
3
2
2
2
0
9
20
16
10
8
6
15
60
20
16
30
4
40
33
20
15
20
14
2
3
1
1
1
3
2
2
2
-------
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Table III
Planned Emissions Classes By Colorado Teachers
#of Projected
Classes or Sec-
tions for 1975
Projected
Dates for
Classes
Length of
Projected
Classes (Hrs)
Types of
Students
Requested
Additional
Training
4
None
1
1
Schedule not
completed
1
1
1
1
1
1
Schedule not
completed
1
1
None
1
Sum, F & W
Fall
Fall
Spring
Fall
Spring
Winter
Fall
Spring
Spring
Fall
Fall
Fall
Not set
9 to 18 hrs,
20
6
20
30
16
30
20
20
20
60
25
14
Not set
Mech. & P.S.
H.S. & P.S.
H. S.
H.S.
Mech. & Coll,
H.S.
H.S.
H.S.
Mech. Teachers
Mech. Coll.
H.S.
H.S.
H.S.
H.S.
Requested Dept.'s
Assistance
Requested Dept.'s
Assistance
Update Training
Requested Dept.'s
Assistance
Update Training
Spark Control
Ford & GM Manuals
Converters
M
<_n
Analyzer & Assistance
-------
26
emission staff or the Health Department in conducting future
emissions training classes.
Development of Proposed Criteria For Investigators and
Inspectors
One of the objectives specified in the contract was for
Colorado State University to develop a proposed criteria
document for state investigator and inspector certification
(see appendix T). The investigators and inspectors
mentioned are those involved with the proposed vehicle
emission inspection/maintenance program in Colorado.
The purpose of the document was to delineate the task
descriptions and responsibilities, and to provide guidelines
outlining the requirements that must be met for investi-
gator and inspector certification. A sequence of procedures
is provided for the investigator and inspector to follow
when application for certification/renewal is made.
Prior to the development of the document considerable
research was done in determining what criteria other
states had developed regarding inspector and investigator
certification. Information from New Jersey, New York
and California, states with emission programs, was gathered
-------
27
the document. Emissions material from several other
states was received but proved of little value as it did
not pertain to vehicle emissions or certification.
An additional effort was made to acquire data by a visita-
tion to Olson Laboratory in California and Hamilton Test
Systems in Phoenix, Arizona.
During the visit to Olson Laboratory they were conducting
an actual emissions inspection for the State of California,
on several state and fleet owned vehicles. The demonstra-
tion witnessed v/as a loaded mode using a Clayton Dyna-
mometer, taking approximately two minutes per test.
California has the inspection maintenance procedure
developed satisfactorily and provided the project team
with their inspection handbook that proved to be the most
useful material received.
In Arizona, Hamilton Test Systems Corporation has been
given a contract by the State to conduct all of the vehicle
emissions inspection program in the private sector for the next
five years. The inspection procedure planned is similar to
California, using the dynamometer to test the vehicle at
55 MPH, 35MPH and idle.
Although Hamilton Test Systems is responsible for conducting
-------
28
training or certification criteria had been developed
that was useful to the project team.
Using the results and recommendations from the Final
Report, March, 1974, on the Pilot Training Program for
Motor Vehicle Emission Control and considering the
responsibilities and duties of the inspector, twelve
(12) hours of training are recommended for inspector
certification. Indicated in Table II of the criteria
document (see appendix T, page 269), the training time
will vary slightly depending upon the applicant's
background.
The forty (40)-hour .training time for investigator
certification was determined by: 1) analyzing teacher
test results, 2) considering investigator's duties and
responsibilities, and 3) assuming the knowledge possessed
by the investigator should be comparable to that of an
automotive instructor. Referring to Table VIII of the
document (see appendix T, page 287) reveals that the
training time varies relative to the type of applicant.
Considering the expenditure of the instructor only Tables
III and VI of the criteria document reflect the estimated
cost per student for training the inspector and investiga-
-------
29
The instructional program cost for the state investigator
and inspector training can be estimated by making the
following assumptions:
(1) Rent, insurance, and utilities for training
facility — $600.00 per month
(2) Equipment: infrared analyzer, scope, hand
and miscellaneous tools -- $5,400.00
(3) Teaching supplies:
a. handouts and training books — $5.00 per
student
b. instructional packet — $240.00
(4) Instructor: $15.00 per hour
Clerical: $ 4.00 per hour
Based on these assumptions, the following Table IV
shows an estimated instructional cost of $1,230.00 for
a forty (40)-hour state investigator and $480.00 for
a twelve (12)-hour inspector training program. The
investigator's training would require ten (10) four-
hour sessions, whereas the inspector would attend four
(4) three-hour sessions.
Table V illustrates the estimated cost of training
one inspector student compared to a varied number of
students in a class. An identical cost per student
comparison for the investigator training is found in
-------
30
TABLE IV
ESTIMATED INSTRUCTION COST FOR
INVESTIGATOR AND INSPECTOR TRAINING
Expenditure
Investigator
10 Session
40-Hr. Training
Inspector
4 Session
12-Hr. Training
Rent, Insurance
Utilities
Equipment
Teaching Supplies *
Instructor
Clerical
$ 200
$ 150
$ 120
$ 600
$ 160
$ 80
$ 60
$ 110
$ 180
$ 50
TOTAL
$1230
$ 480
-------
31
TABLE V
ESTIMATED INSTRUCTION COST ($) PER STUDENT FOR
INSPECTOR TRAINING*
NUMBER OF STUDENTS
IN CLASS
-------
32
TABLE VI
ESTIMATED INSTRUCTION COST ($) PER STUDENT FOR
INVESTIGATOR TRAINING *
NUMBER OF STUDENTS
IN CLASS
-------
33
Public Information
During the course of the project, the Project Director
made three presentations in Colorado, regarding emission
control training. As a guest lecturer, the Project
Director gave an informative presentation to a class
of automotive students at Colorado State University.
Another similar presentation was delivered to a class
of adult education students at Lakewood High School.
Both lecture-presentations covered types of pollutants,
vehicle emission systems found on todays automobiles,
their purpose and basic operation.
In March> the Colorado Automotive Teachers held a meeting
in Denver. The President of the Association asked the
emissions staff from Colorado State University to make
a presentation to the teachers on our emissions instructional
material. A sample of each of the five slide series the
project staff at Colorado State University had developed
was shown and an explanation of our total media program
-------
5.0 ANALYSIS OF TEST RESULTS
This section contains the test results from the Colorado
Vehicle Emission Control Educational Training Program.
The emission training program was provided to twenty-six
(26) automotive teachers in addition to eleven (11)
graduate and undergraduate students. The automotive
teachers were trained in two (2) separate classes. In
August, 1974 a vehicle emissions training class was
conducted for eleven (11) teachers at the Warren Technical
Center in Denver. During the Winter and Spring Quarters
of 1975 another emissions class was offered at the Community
College of Denver Red Rocks Campus for fifteen (15)
automotive teachers. An identical course during the same
period was offered on campus at Colorado State University
to eleven (11) college automotive students. These two
courses were divided into two (2) fifty (50)-hour sections:
Emissions I and II, offered Winter and Spring Quarters
respectively. Emissions I was basically classroom instruc-
tion concentrating on theory, diagnosis, operation of
emission control systems, carburetion and ignition systems
(see appendix o)• The Emissions II class offered the
college students and teachers hands-on laboratory experiences
related to emission control systems service and diagnostic
-------
35
procedures (see appendix 0 ).
At the beginning of all emission classes, except Emissions II,
a pre-test was given to each participant (see appendix S).
This pre-test was divided into four (4) categories:
1) General Engine Theory
2) Emission Systems
3) Carburetion
4) Ignition
The pre-test consisted of fifty-two (52) questions and
the results from the test were used as a guide in deter-
mining the instruction time to be spent in each section.
Shown in Table VII are the mean score results to questions
on the pre-test in each of the four (4) categories.
The table includes the results from the twenty-six (26)
teachers in the class at the Warren Technical Center and
the Emissions I class at Community College of Denver
Red Rocks. From investigation of the table, it becomes
apparent that a concentration of instruction was needed
-------
36
TABLE VII
TEACHER PRE-TEST RESULTS
No. Of
Teachers
Mean sco
re (%) by
category
General
Emission
Systems
Carburetion
Ignition
26
71.8
58.5
71.4
73.8
Information was gathered on the age, teaching and mech-
anical experience of each teacher. Table VIII shows the
average results for these categories.
TABLE VIII
INFORMATION ON TEACHERS CONCERNING AGE,
MECHANIC AND TEACHING EXPERIENCE
Average
Average
No. in
Average
mechanic
teaching
class
age yrs.
experience
experience
yrs.
yrs.
26
37.3
12.2
4.8
The mechanic experience of the teacher did not necessarily
-------
37
teacher with the least amount of mechanic experience,
2 years, missed 21 questions; the teacher with 31 years
of mechanic experience missed 27 questions.
The emissions control class held on campus at Colorado
State University for eleven (11) college automotive
students were given the same pre-test as the teachers.
Table IX provides information on the mean score results
in each category from the pre-test given college students.
TABLE IX
COLLEGE STUDENT PRE-TEST RESULTS
No. of
Students
Mean score (%) by category
General
Emission
Systems
Carburetion
Ignition
11
63. 6
51.3
61.8
71. 7
In addition to the iemissions pre-test the teachers and
college students that took Emissions I during the Winter
Quarter were given an ignition/carburetion pre-test.
As stated earlier in this report, the advent of transistorized
-------
38
of this training to the curriculum. The test contained
forty-five (45) questions related only to ignition and
carburetion. Ten (10) of the forty-five (45) questions
pertained to transistorized ignition systems. Table X
reveals the results from this pre-test given to fifteen
(15) teachers and eleven (11) college students.
TABLE X
IGNITION/CARBURETION PRE-TEST RESULTS
Type of
Average Missed
Mean Score
Mean Score
Participants
(45 pts. possible)
(%)
on Transistor-
ized Ignition
Questions (%)
Automotive
Teachers
9.6
78.6
62
College
Students
11.5
74.4
58
As reflected in Table X the mean score resulting from the
ten (10) questions on transistorized ingition systems
were considerably lower than for the entire test. It
became obvious from the test scores that training was
needed in the transistorized ignition area.
-------
39
and both Emissions I classes for teachers and students#
a post-test was given to each participant. The post-test
was identical to the pre-test. It was administered to
obtain an evaluation on how the participants had progressed
in the areas of vehicle emissions and related categories.
Table XI shows the results from the post-test taken by
the twenty-six (2 6) teachers. The mean scores are listed
for each of the four (4) categories identified earlier.
Although there was a significant improvement in all the
category scores the percentage gain in emission systems was
the highest.
TABLE XI
TEACHER POST-TEST RESULTS
No. Of
Teachers
Mean Scor
•e (%) by CaJ
Legory
General
Emission
Systems
Carburetion
Ignition
26
84.3
73.2
74.4
81.9
The post-test results for the eleven (11) college students
are presented in Table XII. Again, as with the teachers,
the percentage gain in the emissions systems category was the
-------
40
TABLE XII
COLLEGE STUDENTS POST-TEST RESULTS
No. Of
Students
Mean Score by Category
General
Emission
Systems
Carburetion
Ignition
11
76.3
65.6
69.0
79.4
Table XIII provides a comparison of mean scores from the
emissions pre- and post-tests. The teacher and student
scores are both presented with the average gain shown in
the last column.
TABLE XIII
COMPARISON OF PRE AND POST TEST RESULTS
Type of
Participant
Category
Mean Score
Pre-test
Mean Score
Post-test
Average
Gain (%)
General
71.8
84.3
12.5
Teacher
Emission
Systems
58.5
73.2
14.7
Carburetion
71.4
74.4
3.0
Ignition
73.8
81.9
8.1
General
63.6
76.3
12.7
College
Student
Emission
Systems
51.3
65.6
14.3
Carburetion
61.8
69.0
7.2
Ignition
71.7
79.4
-------
41
During the last meeting of the teachers' Emission II class,
a comprehensive type emissions examination was taken by each
of the fifteen (15) automotive instructors (see appendix q).
The test was developed through the efforts of several Colorado
teachers and the emissions staff at Colorado State University.
The examination is comprised of fifty (50) questions dealing
specifically with emission components and systems. The
purpose of the test is to better evaluate the knowledge an
instructor possesses. Table XIV provides the results from
this teacher emission test.
TABLE XIV
RESULTS OF TEACHER EMISSION TEST
No. of
Teachers
Average No.
Missed
Mean
Score (%)
15
12.6
75
As can be seen, the average number of incorrect responses
was 12.6 with the range being from 5 to 20. The test cannot
be expected to be the ultimate answer in testing the knowl-
edge of an instructor; however, some device(s) must be used
and the initial thrust begun at some point. Evaluation and
revisions are a necessity of any testing apparatus if it
-------
APPENDIX A
MOTOR VEHICLE EMISSION CONTROL
-------
43
DELIVERY SYSTEM FOR
INSTRUCTIONAL PROGRAM ON MOTOR VEHICLE
-------
APPENDIX B
FORTY-HOUR COLORADO TEACHER
-------
45
COLORADO TEACHER
MOTOR VEHICLE EMISSION CONTROL WORKSHOP
I. Welcome
A. Registration
B. Introduction of participants and staff
C. Objectives and program
D. Pre-test
II. Pollution Problem, State and Local Laws
A. Mr. Don Sorrels - Colorado Department of Health
B. Film (GM, "Emissions in Perspective")
1. Discuss film
III. Basics of Combustion
A. Definition and Formation of Emissions
1. HC, CO, and NOx
B.- Compression Ratios and Heat
C. Fuels
D. Film ("New Rules of the Road")
1. Discuss film
IV. Engine Modifications to Reduce Emissions
A. Carburetion
B. Camshafts and Timing
C. Combustion Chambers
-------
46
E. Pistons and Heads
F. Film ("Service Up, Emissions Down")
1. Discuss film
V. Emissions Control Systems Identification and Purpose
A. Systems - General, Theory
1. PCV
2. Evaporation
3. Heated Air
4. Carburetor Controls
a. Solenoids
b. Choke
5. Air Injection
6. EGR
7. Ignition Timing Controls
a. Temperature
b. Transmission
c. Ported Vacuum
d. Speed
B. Lab Experience
1. Demonstration on Reading Exhaust Analyzer
a. HC-CO
b. Scale Increments
c. Warm-up of Vehicle
2. Emphasis of Engine Condition on Emissions
3. Hands-on Experience
a. Students Read and Record HC-^CO Levels on
Live Vehicles
C. Film ("Vehicle Emissions Control and Cleaner
Air" and "Auto Emissions Control")
-------
47
VI. Emissions Control Systems
A. PCV Controls
1. Open System
2. Closed System
B. Evaporative Controls
1. Tank Overfill
2. Tank Venting
3. Vapor Trapping Methods - Canisters
C. Heated Air Controls of the Air Cleaner
1. Thermostat Controls
2. Vacuum Motor Controls
D. Intake Manifold Heating
1. Heat Riser Valves
2. Exhaust Pipe Restrictors
3. Coolant Heated Manifolds
E. AIR System
1. Pump Design and Operation
2. Air Delivery Plumbing and Check Valves
3. Routing of Air Delivery by Use of Gulp
Valve, Diverter Valve and Vacuum Signals
During Driving Modes
F. Lab Experience
1. Demonstration: Meter Calibration
2. Effects of Timing and Carburetor Mixtures on HC-CO
G. EGR Controls
1. Exhaust Recycle vs. Engine Operating Modes
-------
48
VII. Identification and Application of Emissions Controls
A. Controls Functioning, During Engine Cranking
1. Distributor and/or retard circuits
2. Solenoid (advance)
3. Dual Vacuum Chamber
B. Controls Functioning at Idle
1. Idle Stop Solenoid - Gets Mixed Up with CEC Valve
2. Chrysler Type Retard Solenoid
3. Dual vacuum Diaphragm
4. 20-second Delay Relay
C. Controls Primarily Functioning in Gears Below High Gear
1. Idle Stop Solenoid
2. Dist. Vacuum Advance Denial Controls
3. Dist. Spark Delay Valves
4. Canister Purge Controls
D. Controls Primarily Functioning in High Gear
1. AIR Controls
2. Decel Valves and Solenoids
3. Idle Circuit Mixture Altering Controls
4. EGR Controls
E. Controls Functioning Above or Below Normal Engine
Operating Temperature
1. Staged Choke Controls
2. Air Cleaner Controls
3. Coolant Temperature Activated Vacuum Valves
-------
49
VIII. GM Emissions Control Systems
A. AIR Induction Control
1. Vacuum Motor and Temperature Sensor
B. AIR Control
1. Pump, Pressure Relief Valve, Check Valve
2. Diverter Valve
C. Ignition Controls
1. TSC
2. CEC
3. SCS
IX. American Motors Emissions Control Systems
A. TCS
B. Decel Valves
C. CTO
D. Lab Experience
1. Worksheet #5
A. Effects of Emissions Hardware
X. Chrysler Control Systems
A. Evaporative Controls
B. Ignition Controls
1. Distributor Solenoids
2. TCS
3. OSAC
4. Decel Valve
C. EGR Controls
-------
50
2. Vacuum Controlled EGR
3. Vacuum Amplifier
XI. Ford Motor Co. Control Systems
A. Evaporative Control
1. Canister and Purge Control
B. Air Induction Control
1. Thermostatic Type
2. Vacuum Motor
C. AIR Control
1. Pump
2. Diverter Valve
D. Ignition Controls
1. Dual Diaphragm Distributor
2. TRS System
3. ESC System
4. TAV System
a. Temperature Sensor
E. EGR System
1. Valve and Control
F. Lab Experience
-------
APPENDIX C
MOTOR VEHICLE EMISSION CONTROL
-------
52
REFERENCE MATERIALS
Booklets
1972 Oldsmobile Emission Control Systems Maintenance,
Oldsmobile Division of GM Corporation.
Servicing 197 3 Buick Emissions Control Systems Reference
Manual.
1973 Dealer Technical Bulletin, Pontiac-GM
1968 Oldsmobile Emission Control Adjustments Manual 802,
Oldsmobile Division of GM Corporation.
Theory and Diagnosis, Emission Controls, Chevrolet.
19 73 Report on Progress in Areas of Public Concern, February
8, 19 73. GM Corporation.
General Motors Emission Control Systems Maintenance Manual,
For Passenger Cars and 1/2 Ton Trucks, General Motors.
19 73 Supplement to General Motors Emission Control Systems
Maintenance Manual, For Passenger Cars and 1/2 Ton
Trucks, General Motors.
1974 Supplement to General Motors Emission Control Systems
Maintenance Manual, For Passenger Cars and 1/2 Ton
Trucks, General Motors.
1973 Emission Controls, Chrysler Corporation Service Training.
Power Service Training, Part III, Emission Control Service,
General Motors.
High Altitude Vehicular Emission Control Program, Vol. VIII,
Final Report, March 19 74.
Federal Register, October 18, 1972, Vol. 37, No. 202, National
Archives.
1975 Colorado Plan for the Control of Motor Vehicle Emissions,
Interim Report, Colorado Department of Health, March
8, 1973.
Interim Report on Pilot Training Programs for Motor Vehicle
Emissions Control, December 1, 1973, Department of
-------
53
Final Report on Pilot Training Programs for Motor Vehicle
Emissions Control, March 1, 1974, Department of
Industrial Sciences, Colorado State University.
Simulated Colorado Handbook, Vol. 1. Automobile Safety
and Emission Control, July 1, 1974.
Motor Vehicle Emissions Control Training Program, Roy
Gillaspy, Colorado State University.
Emission Control Training Program, Students Manual, Mitchell
Manuals, Inc.
Progress Report on Pilot Program for Repairmen on Automotive
Emissions, February 1, 1974. Department of Industrial
Sciences, Colorado State University.
Preliminary Report on the Pilot Training Programs for the
State Investigators and State Inspectors, February
1, 1974. Department of Industrial Sciences, Colorado
State University.
Motor Vehicle Emission Control Decision Development System
Exercise Book, Data Design Laboratories.
Motor Vehicle Emission Control Administrators Guide, Data
Design Laboratories.
Validation Test Plan for Training in Motor Vehicle Emission
Control, Data Design Laboratories.
Emission Control Repair Manual, 1974 Model, Toyota Motor
Sales, Co., Ltd.
Technician Workbook, Toyota HC-CO, Toyota Motor Sales Co.,
Ltd.
19 73 Exhaust Emission Control Manual Supplement, Mitchell
Manuals, Inc.
Chemicals In Our Environment, Marshall Gordon, February 1972.
1974 Tune-Up Specifications, NAPA Echlin.
Test Procedures for Chrysler Electronic Ignition, NAPA Echlin.
1967-74 Engine Tune-Up Chart, Champion Spark Plug Co.
Positive Crankcase Ventilation System Unit.
-------
54
Air Injection System Unit.
Exhaust Gas Recirculation System Unit.
The Clean Air Act and Transportation Controls, Holmes,
Horowitz, Reid, Stolpman, EPA.
Emission Control Systems-Theory, Testing and Service.
"Goodbye to the Great Divide". Satelite Technology Demonstra-
tion, Federation of Rocky Mountain States, Inc.
5 Year Self-Evaluation, 1969-1974, Department of Industrial
Sciences, Colorado State University.
Research in Industrial Arts Education, John Louis Feirer.
Eye Safety in Arizona Education, 1968. Superintendent
of Public Instruction, Phoenix, Arizona.
Application Kit for Grant, U.S. EPA.
Trade and Industrial Educators, June 19 74, Vocational
Education Department, Colorado State University.
1973 Advance National Service Data, Mitchell Manuals, Inc.
Task Analysis of State and Local Air Pollution Control
Agencies and Development of Staffing Guidelines,
U.S. EPA.
Federal Register, Vol. 38, #110, Part III, Requirements for
Preparation, Adoption, and Submittal of Implementation
Plans, EPA.
Inspection and Maintenance of Light Duty, Gasoline-Powered
Motor Vehicles: A Guide for Implementation. U.S.
EPA, August 1974.
A Study of Emissions From 1966-1972 Light Duty Vehicles in
Washington, D.C., 2nd Edition, U.S. EPA.
A Study of Emissions From 1966-1972 Light-Duty Vehicles in
Los Angeles and St. Louis. August 1973, U.S. EPA.
Automobile Exhaust Emission Surveillance-Analysis of the
FY 72 Program, February 1974, U.S. EPA.
Tune-Up and Emission Control Training Manual, 19 72, Atlas.
Vehicle Emission Inspection and Control Program Final Report,
-------
55
Handbook for Installation and Inspection Stations-Pollution
Control Device. Consumer Affairs, Bureau of "Automotive
Repair.
Exhaust Emission Systems, Pontiac Motor Division.
Driveability Booklet No. 1. Basics....Fuel System, Ford
Marketing Corp.
Driveability Booklet No. 1. Basics....Starting System,
Ford Marketing Corp.
Driveability Supplement 2A, Solid State Ignition, Ford
Marketing Corp.
Driveability Booklet No. 2, Basics.... Ignition System, Ford
Marketing Corp.
Driveability Booklet No. 2, Basics....Emission Control
Systems, Ford Marketing Corp.
Vehicle Emission Control Systems, Motorcraft Ford.
Driveability Diagnosis, Ford Marketing Corp.
Emission Monitoring Instruments, Exhaust Gas Analyzer,
Mechanic's Handbook, Toyota.
Introduction to Modulator Control System, Datsun.
Emission Control Systems Maintenance Handbook, Datsun.
Carburetor Diagnosis, Toyota.
Genuine Parts Company, NAPA.
Occupational Learning Systems-Course Descriptions.
High Energy Ignition Systems Training Chart Manual, Delco-
Remy.
The High Energy Ignition System, Delco-Remy.
1974 Adjustment Manual, Delco Carburetor, Delco.
Step-By-Step Servicing of 1.9 Opel Carburetors Reference
Manual, Service Performance Aid.
19 74 Carburetor Course, Cadillac Service Training.
Fundamentals of Automotive Air Conditioning, Chrysler
-------
56
1972 New Model Training, Vehicle Emission Control, IMCO
System, Unit 9, Course 5003, Ford Marketing Corporation.
19 72 New Model Training, Vehicle Emission Control, TRS
System, Unit 10, Course 5004, Ford Marketing Corporation.
1972 New Model Training, Vehicle Emission Control, ESC
System, Unit II, Course 5005, Ford Marketing Corporation.
19 72 New Model Training, Vehicle Emission Control, Carburetor
Adjustments, Unit 12, Course 5006, Ford Marketing
Corporation.
1972 New Model Training, Vehicle Emission Control Maintenance,
Unit 13, Course 500 7, Ford Marketing Corporation.
1973 New Model Exhaust Gas Recirculation System (EGR System),
Course 0323-123,09 01-012, Ford Marketing Corporation.
19 73 New Model Delay Vacuum By-Pass System (DVB System),
Course 0323-124, 0901-013, Ford Marketing Corporation.
Evolution of the Cleaner Air System Session No. 71-10,
Master Technicians Service Conference.
Videocassette
Emission Control Workshop.
Colorado Emission Workshop.
AMA - Clean Air, Chevrolet Div. Service Up Emission Down.
Rules of Road, Auto Emission Control.
Ethyl and GMC Emissions.
Technician Training, 1974 CTP Unit No. 3, Diagnosis of
Driveability Problems, Ford.
National Workshop, Group 5, Thermo Air Cleaner, 1T0185,
A.I.R. Group #3, 190-270, Extra shots, 295-337 (N.G.)
First Colorado Emission Workshop
#1 tape - 1 to 95
#2 tape - 100 to 198
#3 tape - 225 to 325
#4 tape - 330 to 380, 384 to 425
#5 tape - 430 to 465
#6 tape - 468 to 486
-------
57
Chrysler Corporation's Cleaner Air System for 1973 Models,
Chrysler Corporation.
19 73 Emission Controls in the Dodge Truck Line, Chrysler
Service Training.
Electronic Ignition System, Chrysler Corporation Service
Training.
1972 Transmission Controlled Spark Emission System Passenger
Car and 10-30 Truck, General Motors.
Magazines
Highway User Quarterly, Summer, 19 74, Highway Users Feder-
ation for Safety and Mobility.
Motor Magazine, April, 1973; June, 1974.
Tech. Talk, July, 1971.
Industrial Education, October - December, 1973; March -
April, 1974.
Modern Plastics, McGraw Hill, May, 1974.
Man/Society/Technology, AIAA, October - December, 19 73.
American Vocational Journal, September - November, 1973.
Today's Education, September - December, 1973.
School Shop, Ind.-Tech. Education, December, 19 73.
Shop Tips, October, 1970; April, 1973; Spring, 1974;
Summer, 1974.
Filmstrips, Records
1973 New Model Transmission Regulated System + 1 (TRS + 1
System) Course 0323-125, 0901-014, Ford Marketing
Corporation.
19 73 New Model Temperature Actuated Vacuum System (TAC System)
Course 0323-126, 0901-015, Ford Marketing Corporation.
Diagnosis of Driveability Problems, Course 0901-220, Vol.
-------
58
#1 0-94-EGR, 96-250-PCV(NG), National Workshop.
Notebooks
Automotive Emission Control and Tune-Up Procedures, 1972,
Ignition Manufacturers Institute.
Vehicle Emission Control, Instructor's Guide, Gargano.
Chrysler Corporation's Cleaner Air System (1971-1972).
Engine Performance Evaluation With Emission Control Systems
(1971-1972).
Product Information Bulletin: Cleaner Air Package (November,
1964), Air Pollution Control and the Automobile Indus-
try, Reference Book 70-10, 70-5. Chrysler Corporation
Service Training.
Industrial Sciences Retreat 1974, Department of Industrial
Sciences, Colorado State University.
Writing a Unit of Instruction, Bob Patton, State Department
of Vocational and Technical Education.
Instructional Aids and Materials, IT 446.
Industrial Supervision.
Mid-Management 230, Supervisory Techniques.
Fischer-Price Toys, parts list, assembly chart, route sheets,
flow diagram.
E.P.A. National.
North American Conference on Motor Vehicle Emissions
Control II, September 26-28, 1973.
Professional Emission Diagnostic and Safety Manual, Chilton's
Motor Age.
Report on Emission Deterioration and Engine Degradation,
Automotive Testing Labs.
Catalog Descriptions, instructors, texts, course content,
-------
59
Books
Industrial Arts for the Elementary School, 1974, Thrower and
Weber.
Automotive Diagnosis and Tune-Up, Guy F. Wetzel, Mcknight Pub. Co.
Emission Control Manual, Motor's.
Emissions From Combustion Engines and Their Control, D. J.
Patterson and N. A. Henein, Ann Arbor Science Publishers, Inc
Auto Repair Manual, 1971, 1974, Motor's.
Books, American Council for Elementary School Industrial Arts,
ACESIA, 19 71.
Mobile Hydraulic Testing, Glenn and Blinn.
Glenn's Emission Control Systems, Harold T. Glenn.
Emission Control Training Program,. Introduction, Description,
Operation, Mitchell Manuals, Inc.
Problems in Operations Management, Cotlar, DuMont, Richman.
A Study of Emissions From Light Duty Vehicles in Six Cities,
APTD, 1947, U.S. E.P.A.
Study of Softwood Sawlog Conversion Efficiency and the Timber
Supply Problem, U.S. Department of Agriculture, Forest
Service.
Abatement and Pollution Control Training and Educational Programs,
July, 1973 - June, 1975, U.S. E.P.A.
Environmental Information Systems Directory, June, 19 73, U.S.
E.P.A.
The Story of Gasoline, Ethyl Corporation.
Waste Automotive Lubricating Oil As a Municipal Incinerator Fuel,
September, 1973, E.P.A.
Guide for Compiling a Comprehensive Emission Inventory, U.S. E.P.A.
June, 1972, March, 1973.
Field Operations and Enforcement Manual for Air Pollution Control,
Volume I, U.S. E.P.A.
Guide to Technical and Financial Assistance for Air Pollution
Control, APTD - 1119, U.S. E.P.A.
Guidelines for Technical Services of a State Air Pollution Control
-------
60
Automobile Exhaust Emission Surveillance, A Summary, APTD -
1544, U.S. E.P.A.
Effectiveness of Short Emission Inspection Tests in Reducing
Emissions Through Maintenance, E.P.A. - 460/3-73-009,
U.S. E.P.A.
Transmission Study for Turbine and Rankine Cycle Engines,
APTD - 1558, U.S. E.P.A.
Air Pollution Technical Publications of the U.S. E.P.A.,
January, 1974, Air Pollution Technical Information Center.
Exhaust Emissions From Uncontrolled Vehicles and Related
Equipment Using Internal Combustion Engines, U.S. E.P.A.
Automotive Exhaust Crankcase Emission and Fuel Evaporation
Emission Control Service Manual, Mitchell Manuals,
1969, 1973.
National Service Data Domestic, 1973, Mitchell Manuals.
Catalogs
Service Training Aids Catalog, Ford Marketing Corporation.
Booklet, Record
What You Must Know About AMC Emission Controls Release,
74-1, 2, 3, American Motors.
Charts
Anti-Stall Dashpot Adjustment, Fast Idle Adjustment, Ford
Marketing Corporation.
Idle Speed Adjustments, Ford Marketing Corporation.
Diagnosis of Emission Systems, Ford Marketing Corporation.
Pamphlets
1974 Emission Controls - Dodge Truck, Chrysler Service Training.
Chrysler Corporation's Cleaner Air System for 1974 Models -
-------
61
Electronic Ignition System - Student Quiz, Chrysler Service
Training.
1973 Emission Controls - Student Quiz, Chrysler Service
Training.
19 73 Emission Controls - Dodge Trucks, Instructor's Handbook,
Chrysler Service Training.
Technical Service Bulletin, Chrysler Corporation.
Instructor's Outline, 19 73 Emission Controls (Passenger Car),
Chrysler Corporation Service Training.
Service Technical Training Aids, American Motors Sales
Corporation.
Instructor's Outline, 1973 Emission Controls (Dodge Trucks),
Chrysler Corporation Service Training.
Facts on Car Care, Firestone Training Department.
Clean-Air Tune-Ups with Infrared HC/CO Emissions Analysis,
Kal-Equipment Company.
Technical Notes: Positive Crankcase Ventilation, Ethyl
Corporation.
Technical Notes: Controlling Exhaust Emissions, Ethyl
Corporation.
Service Meeting Guide, Diagnosis of Driveability Problems,
Volume 72, S6-L1, Course 0901 - 220, Ford Marketing
Corporation.
1973 Service Highlights, Ford Marketing Corporation.
Diagnosis of Driveability Problems, Volume 72, S6-L2, Ford
Marketing Corporation.
Vehicle Emission Control, TRS System, Course 0901, 004-FRB1,
Ford Marketing Corporation.
Vehicle Emission Control, ESC System, Course 0901, 004-FRB2,
Ford Marketing Corporation.
Vehicle Emission Control, IMCO System, Course 0901, 003-FRB1,
Ford Marketing Corporation.
Vehicle Emission Control Maintenance, Course 500 7, Ford
-------
62
Vehicle Emission Control, Carburetor Adjustments, Course
5006, Ford Marketing Corporation.
Vehicle Emission Control, Introduction, Fuel Evaporation
and Crankcase Emission Control Systems, Course 5002,
Ford Marketing Corporation.
Concrete Masonry Pictorial Shopping Centers, Colorado
Concrete Masonry Association.
The Echlin Story, NAPA Echlin.
Ignition Service Bulletin, NAPA Echlin.
Electrical Service Manual, NAPA Echlin.
Bulletin of Information Fall 1974, Voluntary Mechanic Testing
and Certification, National Institute of Automotive
Service Excellence.
Tune-Up Equipment Operation Manual, Basic.
Your Car and Clean Air, Automobile Manufacturers Association.
Slides
Fundamentals of Air Conditioning.
Transparencies
Automotive Emission Control Systems, DCA Education Products
Inc.
Vehicle Emission Control.
Book, Cassette Tape, Slides
Emission Control Training Program Maintenance and Servicing,
-------
APPENDIX D
MOTOR VEHICLE EMISSION CONTROL
-------
64
CARBURETOR TRANSFER & ANALYZER READINGS
Motor Vehicle Emissions Control Workshop
Lab Worksheet No. 1
Name Team #
Record HC-CO levels from live vehicles at the engine speeds
indicated.
Car #1
HC (ppm)
CO (%)
IDLE
1100 RPM
1200 RPM
1300 RPM
14 00 RPM
2500 RPM
Car #2
HC (ppm)
CO (%)
IDLE
1100 RPM
1200 RPM
1300 RPM
1400 RPM
2500 RPM
Car #3
HC (ppm)
CO (%)
IDLE
1100 RPM
1200 RPM
1300 RPM
1400 RPM
2500 RPM
-------
65
TIMING
Motor Vehicle Emissions Control Workshop
Lab Worksheet No. 2
Name Team #
Record HC-CO levels from live vehicles at speeds arid conditions
listed.
ENGINE SPEED
CONDITION INDUCED
HC (ppm)
CO (%)
1. Idle
Ignition timing at
manufacture "specs"
2. 1100 RPM
Same as #1
3. 2500 RPM
Same as #1
4. Idle
Ignition timing ad-
vanced 5 degrees
over "sp^rs"
5. 1100 RPM
Same as #4
6. 2500 RPM
Same as #4
7. Idle
Full manifold vacuum
applied to vacuum
advance unit
8. 1100 RPM
Same as #7
9. 2500 RPM
Same as #7
RESET TIMING TO MANUFACTURER'S "SPECS"
L0. Idle
One spark plug wire
disconnected
11. 1100 RPM
One spark plug wire
disconnected
12. Idle
Adjust carburetor
idle mixture screws
until lowest HC and
CO combination is
obtained
-------
66
Page 2, Lab Worksheet #2
ENGINE SPEED
CONDITION INDUCED
HC (ppm)
CO (%)
13. Idle
Turn both I.M.S. one
turn lean from #12
test
RESET I.M.S. TO LEAN BEST IDLE CONDITION
14. Idle
Turn both I.M.S. one
turn rich
RESET I.M.S. TO LEAN BEST IDLE CONDITION
15. Idle
Turn right I.M.S. one
turn lean; turn left
I.M.S. one turn rich
RESET I.M.S. TO LEAN BEST IDLE CONDITION
16. Idle
Adjust idle mix screws
until lowest CO
reading is reached
-------
67
Page 3, Lab Worksheet #2
1. Explain the effects of advanced timing on:
a. CO
b. HC
2. Explain the variance between the HC and CO readings for:
a. One plug wire disconnected at idle as compared to all
connected
b. One plug wire disconnected at 1100 RPM as compared,
to all connected
3. Explain variance between the HC and CO readings for:
a. Both carb screws lean
-------
68
FUEL PRESSURE
Motor Vehicle Emissions Control Workshop
Lab Worksheet No. 3
Name Team #
Record HC-CO levels from live vehicles at speeds and conditions
listed.
ENGINE SPEED
CONDITION INDUCED
HC (ppm)
CO (%)
1. Idle
Normal Fuel Pump Pressure
Normal Fuel Pump Volume
2. Idle
Fuel Pump Pressure Two
PSI less than in #1
3. 2500 RPM
Fuel Pump Pressure Two
PSI less than in #1
4. Idle
Fuel Pump Pressure 1/2
Value of Reading in
#1
5. 2500 RPM
Fuel Pump Pressure 1/2
Value of Reading in
#1
6. 1500 RPM
Reduce Fuel Pump Pres-
sure Gradually Until
Distinct Changes in HC
and/or CO Readings occur
and record levels Fuel
Pump Pressure
7. Idle
Disconnect at Carburetor
the vacuum hose for the
Thermostatic Air Cleaner
(Air Leak: carburetor)
8. 2500 RPM
Same condition as #7
-------
69
Page 2, Lab Worksheet #3
ENGINE SPEED
CONDITION INDUCED
HC (ppm)
CO (%)
9. Idle
Remove Vacuum Tap Plug
from manifold (Localized
Air Lead)
10. Idle
Connect Vacuum Gauge
to Engine: Loosen Base
Nuts on carburetor and
cause Vacuum Reading to
drop 5" from normal
reading
11. Cranking
No leaks or disconnected
hoses; record cranking
vacuum
Vacuum
\
/
12. Cranking
Remove PCV Valve hose
from vacuum source
Vacuum
/
\
13. Idle
Plugged PCV Valve
14. 1100 RPM
Plugged PCV Valve
15. 2500 RPM
Plugged PCV Valve
16. Idle
PCV Valve Removed
17. 1100 RPM
Same as #16
18. 2500 RPM
Same as #16
-------
7 0-
TRANSMISSION SWITCH S IDLE
Motor Vehicle Emissions Control Workshop
Lab Worksheet No. 4
Name Team #
Record HC-CO levels from live vehicles at speeds and conditions
listed.
.ENGINE SPEED
CONDITION INDUCED
HC (ppm)
CO (%)
1. Idle
Adjust idle mixture
screws until lowest
HC-CO combination is
obtained.
2.
Raise rear wheels up
and place on stands.
Shift to drive position
and accelerate slowly
noting at what RPM the
transmission shifted
into high. Maintaining
this speed and RPM take
readings.
3.
Transmission in neutral
and same RPM as in #2.
4.
Manifold vacuum when
transmission is in high.
(Same as #2)
Vacuum
-5.
Transmission in neutral
and RPM at same speed
as in #2 and #3.
Vacuum
6.
Adjust idle speed and
mixture to "specs."
7.
Idle speed 25 RPM below
"specs."
-------
71
Page 2, Lab Worksheet #4
ENGINE SPEED
CONDITION INDUCED
HC (ppm)
CO (%)
8.
Idle speed 50 RPM
below "specs."
9.
Idle speed 75 RPM
below "specs."
10.
Idle speed 25 RPM
above "specs"
11.
Idle speed 50 RPM
above "specs."
12.
Idle speed 75 RPM
above "specs."
13. Idle
13a. 1100 RPM
13b. 2500 RPM
None (Reference)
None (Reference)
None (Reference)
14.
Heat door closed on
air cleaner.
15. 1100 RPM
Heat door closed
on air cleaner.
16. 2500 RPM
Heat door closed on
air cleaner.
VEHICLE ON DYNO LOAD
17. 1100 RPM
Plug air filter by
wrapping tape around
it until HC-CO read-
ing changes from #13
reading.
13. 2500 RPM
Same as #17 (use read-
ings in #13 as refer-'
ence)
-------
72
EVAPORATIVE & AIR SYSTEMS
Motor Vehicle Emissions Control Workshop
Lab Worksheet #5
Name Team #
ENGINE SPEED
CONDITION INDUCED
HC (ppm)
CO (%)
1. Idle
All Systems Normal
(Reference)
2. 1200 RPM
All Systems Normal
(Reference)
3. 2500 RPM
All Systems Normal
(Reference)
4. Idle
Canister Purge Line
Disconnected and
Plugged
5. 1200 RPM
Canister Purge Line
Disconnected and
Plugged
6. 2500 RPM
Canister Purge Line
Disconnected and
Plugged
7. idle
Disconnect Drive Belt
or Delivery Hose(s)
From AIR Pump to
Exhaust Manifold(s)
8. 1200 RPM
Same as #7
9. 2500 RPM
Same as #7
-------
73
Page 2, Lab Worksheet #5
ENGINE SPEED
CONDITION INDUCED
HC (ppm)
CO (%)
10. 1200 RPM
Decelerate Quickly
and Note Highest HC-CO
Readings
11. 1200 RPM
Disconnect and Plug Vacuun
Line To AIR By-Pass Valve;
Decelerate and Note High-
est HC-CO Readings
12. Idle
Disconnect any Manifold
Vacuum Hose and Pour in
a Few Crops of Chem-Tool
Cleaner into Line
13. Idle
Squirt Small Amounts of
Chem-Tool Around Carbure-
tor Throttle Shaft Bush-
ings
14. 1000 RPM
Disconnect One Spark Plug
Wire at a Time Noting HC-
CO Readings. (Run Test
Like a Cylinder Balance
Test)
Cylinder
#
1
2
3
4
5
6
7
8
-------
74
DIAGNOSTIC
Motor Vehicle Emissions Control Workshop
Lab Worksheet No. 6
Name Team #
ENGINE SPEED
CONDITION INDUCED
HC (ppm)
CO (%)
1. Idle
Do Not Calibrate or Span
Analyzer After Warm-Up
and Run HC-CO Test
2. Idle
Calibrate and Span
Analyzer and Repeat
Test #2
3. Engine
Stopped
After Engine Has Warmed
Up to Operating Temper-
ature, Use Probe of
Analyzer to Sniff Out
Fuel Vapor and Liquid
Leaks Around the Follow-
ing :
a. Fuel Pump, Fittings
and Hose
b. Carburetor
c. Fuel Tank
d. Charcoal Canister
4. 1000 RPM
Disconnect All Plug Wires
to Cylinders Fed by Right
Carb. Barrel
5. 1000 RPM
Disconnect all Plug Wires
to Cylinders Fed by Left
Carb. Barrel
6. Idle
All Systems Normal Adgust
to Lean Best Idle.
7. 1200 RPM
Normal
-------
75
Page 2, Lab Worksheet #6
ENGINE SPEED
CONDITION INDUCED
HC (ppm)
CO (%)
8. 1500 RPM
Normal
9. 2500 RPM
Normal
10. Idle
Vacuum to EGR to Trip
Open Manually
11. Idle
Disconnect and Plug
Vac. Line to EGR Valve
12. 1200 RPM
Disconnect and Plug Vac
Line to EGR Valve
•
13. 15 RPM
Disconnect and Plug Vac
Line to EGR Valve
•
14. 2500 RPM
Same as #13
-------
APPENDIX E
-------
77
ASSUMPTIONS
The motor vehicle emission control instructional materials
packet is designed to be used by vocational automotive
teachers. These teachers are expected to supplement this
instructional packet with models, mock-ups, films, charts,
and hands-on experiences. These materials cover the
following motor vehicle emission control systems in depth:
Air Injection Reaction, Exhaust Gas Recirculation, Fuel
Evaporation, Positive Crankcase Ventilation, and Thermo-
static Air Cleaner.
Utilizing tests and subjective evaluation, the teacher
should be able to determine the depth of material to be
presented. This depth will be dictated by the needs of
the participants. The length of the instruction will
depend upon the participants' ability.
The following assumptions were considered in the develop-
ment of the instructional materials packet.
1. Instructional materials are designed for teacher use.
2. Teachers will be familiar with carburetion, elec-
trical, and engine theory.
-------
78
Teachers will be familiar with electrical test
equipment.
Teachers will be familiar with diagnostic pro-
cedures .
Teachers will be familiar with the effective
use of instructional media.
-------
APPENDIX F
MOTOR VEHICLE EMISSION CONTROL
t
-------
80
EMISSIONS COURSE OUTLINE FOR AUTOMOTIVE INSTRUCTORS
I. Introduction
A. Air Pollution - cause and effect
1. KC, CO, NOx - defined and explained
2. Basics of Combustion Engine Operation and
Emissions.
3. Formation of Emissions in Pre-Controllea Vehicles,
a. Film: Chemistry of Combustion
4. External Controls to Reduce Emissions
a. Function and Purpose of Each
1) positive crankcase ventilation
2) heated air intake
3) transmission controlled spark
4) fuel evaporative system
5) air injection system
6) exhaust gas recirculation
7) catalytic converter
8) thermal reactor
9) high energy ignition
B. Laws and Regulations
1. State
2. Federal
3. Inspection/Maintenance
-------
81
systems of cars in shop using EPA systems
book.
C. Introduction to Infrared Analyzer
1. Principles of Operation
2. Pre-Testing Preparations
a. engine at normal operating temperature
b. correct calibration and span
c. correct hook-up
3. Care
a. filters
b. volume of air flow check
c. hose and fitting leaks
4. Lab Experience
a. on car testing
1) HC-CO readings from live lab cars.
Ignition Systems
A. Pre-Controlled Systems
1. Theory and Purpose of Ignition System
a. basic electricity
1) volts, amps, ohms
b. ignition system components; construction
and operation
c. diagnostic procedure in locating problems
1) emissions vs. ignition
-------
82
1. Ignition Timing Effects on Emissions
a. HC, CO. NO
' x
b. advance controls for reducing emissions
1) dual diaphragms
2) electric solenoids controlling vacuum
supply
3) modified advance curves
4) lab experience: ignition timing
changes and effects on HC-CO emissions
C. Electronic Ignition
1. Purpose and Advantages
2. Theory of Operation
a. component identification (general to all
manufacturers)
3. Specific Manufacturers Systems
a. Chrysler
1) component testing
b. GM
1) component testing
c. Ford
1) component testing
III. Carburetion Systems
A. Pre-Controlled
1. Carburetion Principles
-------
83
1) purpose of vacuum
b. carburetor vacuum principles
1) types of vacuum
a) manifold
b) ported
c) venturi
c. carburetor circuits
1) jetting and power valves
a) effects, advantages, disadvantages
d. air cleaners
1) filters
e. fuel system demands
1) engine speed and load vs. fuel require-
ments
f. diagnostic procedure
1) locating problem area
B. Carburetor Modifications
1. Idle Mixture Limiters
a. purpose as related to HC-CO
2. Idle Stop Limiters
a. function
3. Combination Valves (C.E.C.)
a. operational checks and function
b. decel valves
4. Venting
a. internal
-------
84
Adjustments and Service
a. idle mixture screws
b. float level
c. idle and deceleration speeds
Chokes: Checks and Adjustments
a. vacuum breaks
b. water heated
c. electric
d. staged
e. lab experience
1) effects of lean and rich mixtures on
HC-CO
2) set
a) idle mixture screws for lean-best
idle
b) check choke "specs"
c) idle stop solenoids
Exhaust Restrictions and Controls
a. heat riser
1) service
2) vacuum operated type
b. restrictor pipes
c. exhaust system problems
Engine Modifications
-------
85
A. Cam Shafts
1. Overlap Variations
a. purpose and function
B. Valves, Ports, and Valve Arrangement
C. Intake Manifolds
1. heat ribs
2. water heated
3. crossover passage
D. Exhaust Manifolds
1. flow design
a. with air injection
2. scavanging
E. Combustion Chambers
1. Reduction of Quench Area
a. changes in contoured shape of combustion
chamber
1) reduction of quench area with improved
head gaskets
b. closer parts mating
c. piston ring placement and alteration
d. compression ratio modification and effects
relating to HC and CO
1) cylinder heads
2) effects on combustion temperature-NOx
3) temperature effects on emissions-NO
-------
86
1. Operating Temperature Changes
a. 1963-72 models
b. .1972-75
2. Effects of Pressure Caps on System
a. sealed systems
Positive Crankcase Ventilation (PCV)
A. Principle and Purpose of Crankcase Ventilation
C.S.U. Slides: "P.C.V."
B. Types of Ventilation Control
1. Type 1: Open-Valve controlled by intake manifold
vacuum.
2. Type 2: Open-Valve controlled by crankcase
vacuum. (West Coast type valve)
3. Type 3: Open-Tube to Air Cleaner
4. Type 4: Closed-Combination System
a. hose routing
5. Correct P.C.V. Valve Application by Model and
Year
a. servicing and checking
C. Lab Experience:
1. effects of P.C.V. on eimissions
2. HC-CO readings with correct, incorrect, plugged
and open P.C.V. valves
-------
87
A. Principle and Purpose of T.A.C.
Slides: C.S.U. - "T.A.C."
1. Better Cold Operation Driveability
2. Leaner Air/Fuel Mixtures
3. Reduction of Emissions HC and CO
4. Lab Experience: Check hose routing and condition,
proper door operation, temperature sensor and
vacuum motor.
a. thermostatic type: check thermostat operat-
ing temperatures
VII. Air Injection Systems
Slides: C.S.U. A.I.R.
A. System Components
1. Pump Design and Operation
2. Air Delivery Plumbing and Check Valves
3. Pressure Relief Valves
4. Gulp Valves and Operation
5. Routing of Air Delivery by Use of Diverter Valve
a. diverter valve operation
b. vacuum signals to diverter valve generated
by driving modes
lab experience:
1) effects of A.I.R. on HC-CO analyzer
readings with A.I.R. functioning
-------
88
c. checking and testing:
1) check hose routing
2) pump output
3) check valve operation
4) relief valve
5) diverter valve operation
VIII. Fuel Evaporative System
Slides: C.S.U. Fuel Evaporative Systems
A. Fuel Tanks
1. Tank Expansion Space
2. Filler Neck Location Limiting Overfill
3. Tank Venting
4. Caps: No Vent and Pressure Relief
a. vacuum and pressure relief valves
B. Liquid Vapor Separators
1. ' Tube-Type
2. Separator with Float
C. Fuel Line:
1. Routing and Construction
2. In Line Valves
a. overfill limiting valves
b. 3-way combination valves (Ford)
D. Vapor Storage
1. Crankcase
-------
89
2. Carbon Canister
a. construction and purpose
b. connections and location
c. service of canister
d. purge methods
1) variable
2) constant
3) combination constant-demand
3. Carburetor Bowl Venting
a. carburetor vent valve
b. routing of vent vapors to canister
4. Lab Experience - Check and Test
a. hose routing and type of evaporative system
b. check leaks with HC and CO meter
c. canister and filters
d. fuel tank cap
Spark Controlled Systems
A. Purpose, Similarity and Differences by Manufacturers
1. Reduction of HC, CO, NO
A
2. The Necessity of Manuals and Specifications
B. Ignition Timing Controls
1. Temperature Switches (Ambient and Coolant)
2. Transmission Switches
3. Ported Vacuum
4. Speed Sensors (In Cable)
-------
90
5. Solenoids
6. Time Relays
7. Spark Delay Valves (Vacuum)
8. Distributor Vacuum Advance Control Valve (De-
celeration)
9. Overheat Protection Devices and Switches
C. American Motors System
Slides: Mitchell Manuals
1. Spark Control Systems
a. principles of transmission controlled spark
system
1) solenoid vacuum valve
2) transmission switches
3) temperature switches
4) vacuum and electrical circuits
D. General Motors System
Slides: Mitchell Manuals
1. Principles of Spark Control Systems
a. transmission controlled spark (TCS)
1) vacuum advance solenoid
2) transmission switch
3) temperature switch
4) delay relay
b. combination emission control (CEC)
1) CEC solenoid
2) idle stop solenoid
-------
91
4) 20 second time relay
5) temperature switch
c. speed controlled spark (SCS)
1) speed control switch
2) vacuum solenoid
3) thermal vacuum switch
2. Lab Experience
E. Chrysler System
Slides: Mitchell Manual
1. Principles of Spark Control Systems
a. vacuum advance control valve (deceleration)
b. distributor advance solenoid
c. retard distributor retard solenoid
d. NC>x system (1971-72)
1) solenoid vacuum valve
2) transmission switches
3) vacuum and thermal switches
4) speed switch
e. orifice spark advance control system
(1973-)
1) OSAC valve
2) temperature sensor
3) vacuum by-pass valve
-------
92
Ford System
Slides: Mitchell Manuals
1. Principles of Spark Control Systems
Film: Ford ESC
a. electronic spark control system
1) speed sensor
2) electronic amplifier
3) solenoid vacuum control valve
4) temperature switch
5) ported vacuum switch (PVS)
b. transmission regulated spark (TRS)
1) vacuum control valve
2) transmission switch
3) ambient temperature switch
4) ported vacuum switch (PVS)
5) spark delay valve
6) dual diaphragm distributor
c. EGR/CSC system
1) port and EGR vacuum
2) coolant temperature PVS
3) spark delay valve
4) check valve
5) EGR/PVS valve
6) overheat protection
a) thermal vacuum switches
-------
93
X. Exhaust Gas Recirculation (EGR)
A. Purpose and Principles
1. Reduce NO
x
2. Reduce Combustion Temperature
Slides: C.S.U. and Mitchell Manual
B. EGR Controls
1. Exhaust Recycle Requirements vs. Engine Operating
Modes
2. EGR Delivery and Metering
a. floor jets
b. floor entry
1) EGR valve operation
3. Vacuum Signal Operation of EGR
a. cold override
b. control of EGR at idle
c. wide open throttle
1) vacuum and cut-off controls
d. vacuum amplifier
1) purpose and operation
e. exhaust pressure transducer
f. servicing EGR valve
C. Lab Experience: Check and Test
1. hose routing and connections
2. vacuum source valves
3. CTO switch operation
-------
94
5. vacuum reservoir
6. EGR valve
XI. Catalytic Converters
A. Construction and Chemical Principle
1. Pellet
2. Monolith
3. Precautions Due to Converter
a. shielding
b. insulation
c. heat
d. operating temperature - pellet monolith
e. damage due to:
1) fuel
2) heat
3) harmful diagnostic practices
4) moisture
5) road hazard
6) output of hazardous materials
f. HC-CO testing on converter equipped vehicles,
XII. New and Upcoming Auto Emission Devices
A. Carburetion
1. Carburetor Modifications
-------
APPENDIX G
MOTOR VEHICLE EMISSION CONTROL
-------
96
AIR INJECTION REACTION
Behavioral Objectives
Upon completion of the slide series and instructor-related
teaching materials, the student will be able to:
1. Identify the process in which the Air Injection Reaction
system reduces pollution from the automobile engine.
1.1 State how the Air Injection Reaction system is
effective in reducing engine emissions.
1.2 Name the harmless gas created by the Air Injection
Reaction system in the exhaust manifold.
1.3 State how water is formed in the exhaust system
by the Air Injection Reaction system.
1.4 Name the two ways air is obtained by the air pump
for delivery to the Air Injection Reaction system.
1.5 State the two ways of routing the air to the
exhaust system.
2. Identify and state the purpose of each component that
comprises the Air Injection Reaction system.
2.1 Identify and state the purpose of the air pump.
2.2 Identify and state the purpose of the diverter
valves.
2.3 Identify and state the purpose of the gulp valve.
2.4 Identify and state the purpose of the anti-
backfire valve.
2.5 Identify and state the purpose of the air by-pass
valve.
3. Identify and state the function of each component that
comprises the Air Injection Reaction system.
3.1 State the function of the air pump in the Air
-------
97
3.2 State the function of the diverter valve in the
Air Injection Reaction system.
3.3 State the function of the gulp valve in the Air
Injection Reaction system.
3.4 State the function of the anti-backfire valve in
the Air Injection Reaction system.
3.5 State the function of the air by-pass valve in
the Air Injection Reaction system.
State the inspection and maintenance procedure for
the Air Injection Reaction system.
4.1 State the inspection and maintenance required by
the air injection inlet filtering element.
4.2 State the inspection and maintenance procedure
for tightening the air pump drive belt.
4.3 State the procedure used to inspect the complete
Air Injection Reaction system.
4.4 State the procedure used to inspect the check
valve.
4.5 State the procedure used to inspect the air pump
discharge.
State the testing procedures for each component of
the Air Injection Reaction system.
5.1 State the procedure used to test the air pump.
5.2 State the procedure for testing the gulp valve.
5.3 State the procedure used to test the diverter
valve.
5.4 State the procedure for testing the check valve.
5.5 State the procedure for testing the Air Injection
-------
EXHAUST GAS RECIRCULATION
Behavioral Objectives
Upon completion of the slide series and instructor-related
teaching materials, the student will be able to:
1. Identify the process by which the exhaust gas recircula-
tion system reduces pollution from the automotive
exhaust.
1.1 Identify the three major components of air and
their respective percentage.
1.2 State the definition of an inert gas.
1.3 State the conditions at which nitrogen will
react with other gases.
1.4 State the date which the automobile industry
first started using the exhaust gas recirculation
system.
1.5 State the amount of N0x pollutants allowed by
the current federal standards.
2. Identify and state the purpose of each component
that comprises the exhaust gas recirculation system.
2.1 Identify and state the purpose of the exhaust
gas recirculation valve.
2.2 Identify and state the source of vacuum used to
control the exhaust gas recirculation valve.
2.3 Identify and state the purpose of the pintle
and pintle seat.
2.4 Identify and state the purpose of the EGR-CTO
switch.
2.5 Identify and state the purpose of the transducer.
2.6 Identify and state the purpose of the vacuum
amplifier.
-------
99
3. Identify and state the function of each component
that comprises the exhaust gas recirculation system.
3.1 State the function of the EGR valve.
3.2 State when vacuum is made available to the EGR
valve.
3.3 State the function of the applied vacuum to the
EGR valve.
3.4 State the function of the EGR-CTO switch.
3.5 Identify and state the function of the vacuum
amplifier.
4. State the inspection and maintenance procedures for
each component of the exhaust gas recirculation system.
4.1 State intervals the EGR valve should be inspected.
4.2 State intervals EGR valve should be cleaned and/
or replaced.
4.3 State reasons for inspecting and/or replacing
vacuum lines.
4.4 State the type of maintenance required for each
component of the EGR system.
4.5 State four reasons that can create malfunctioning
of EGR valve.
5. State the testing procedures for each component of
the exhaust gas recirculation system.
5.1 State procedures used for testing EGR valve.
5.2 State procedures used for testing EGR-CTO
switch.
5.3 State procedures used for testing EGR transducer.
5.4 State two purposes of vacuum readings used in
test procedures.
5.5 Successfully conduct testing procedures utilizing
-------
FUEL EVAPORATIVE CONTROL
Behavioral Objectives
Upon completion of the slide series and instructor-related
teaching materials, the student will be able to:
1. Identify the process in which the Fuel Evaporative
Control system reduces pollution from the automobile.
1.1 Name the two areas of the automobile that hydro-
carbon vapors dissipate.
1.2 State the period during which the most evaporative
losses occur from the automobile.
1.3 State the year that all automobile manufacturers
equipped their vehicles with evaporative control
devices.
1.4 State how the Fuel Evaporative Control system
reduces the entrance of hydrocarbon vapors into the
atmosphere.
1.5 State the approximate percentage of the total
automobile emissions that are contributed by
the gasoline hydrocarbon vapors that evaporate
from the carburetor and fuel tank.
2. Identify and state the purpose of each component that
comprises the Fuel Evaporative Control system.
2.1 Identify and state the purpose of the fuel tank
filler cap.
2.2 Identify and state the purpose of an external
expansion tank.
2.3 Identify and state the purpose of a liquid vapor
separator.
2.4 Identify and state the purpose of the carbon
canister.
2.5 Identify and state the purpose of the three-way
overfill valve.
-------
101
3. Identify and state the function of each component
that comprises the Fuel Evaporative Control system.
3.1 State the function of the fuel tank filler cap
in relation to both pressure and vacuum.
3.2 State the function of the internal and external
expansion tanks.
3.3 State the function of the liquid vapor separator.
3.4 State the function of the carbon canister.
3.5 State the function of the three-way overfill valve.
4. State the inspection and maintenance procedures for the
Fuel Evaporative Control system.
4.1 State the inspection procedure used to inspect
the fuel tank filler cap.
4.2 State purpose for inspecting hoses and connections
of Fuel Evaporative Control system.
4.3 State the procedure for inspecting the carbon
canister.
4.4 State the procedure for inspecting the liquid
vapor separator.
4.5 State procedure used to inspect three-way overfill
valve.
5. State the testing procedures for each component of the
Fuel Evaporative Control system.
5.1 State the procedure used to test the fuel tank
filler cap.
5.2 State the procedure used to test the liquid vapor
separator.
5.3 State the method used to test the three-way
overfill valve.
5.4 State procedure to be used when inspecting carbon
canister.
-------
102
POSITIVE CRANKCASE VENTILATION
Behavioral Objectives
Upon completion of the slide series and instructor-related
teaching materials, the student will be able to:
1. Identify the process in which the Positive Crankcase
Ventilation system reduces pollutants from the auto-
mobile engine.
1.1 Name the four types of Positive Crankcase Ventila-
tion systems.
1.2 State steps utilized by the type I Positive
Crankcase Ventilation system for crankcase
ventilation.
1.3 State steps utilized by the type II Positive
Crankcase Ventilation system for crankcase
ventilation.
1.4 State steps utilized by the type III Positive
Crankcase Ventilation system for crankcase
ventilation.
1.5 State steps utilized by the type IV Positive
Crankcase Ventilation system for crankcase
ventilation.
2. Identify and state the purpose of each component
that comprises the Positive Crankcase Ventilation system.
2.1 Identify and state the purpose of the Positive
Crankcase Ventilation Valve in the backfire
position.
2.2 Name the three harmful blow-by products controlled
by the Positive Crankcase Ventilation system.
2.3 Identify and state the purpose of the Positive
Crankcase Ventilation Valve.
2.4 Identify and state the purpose of the West Coast
Control Valve.
2.5 Identify and state the purpose of the two filtering
elements found in the Positive Crankcase Ventila-
-------
103
3. Identify and state the function of each component
that comprises the Positive Crankcase Ventilation
system.
3.1 State the function of the backfire position
of the Positive Crankcase Ventilation Valve.
3.2 State the function of the Positive Crankcase
Ventilation Valve.
3.3 State the function of the West Coast Control
Valve.
3.4 State the function of the Positive Crankcase
Ventilation Valve during the three basic modes
of operation.
3.5 State the function of the filtering elements found
in the Positive Crankcase Ventilation system.
4. State the inspection and maintenance procedures for
the Positive Crankcase Ventilation system.
4.1 State the procedure used to inspect the two
filtering elements found in the Positive Crank-
case Ventilation system.
4.2 State the recommended maintenance required by
the two filtering elements.
4.3 State the procedure used to inspect the Positive
Crankcase Ventilation Valve.
4.4 State the recommended maintenance required by
the Positive Crankcase Ventilation Valve.
4.5 State the recommended inspection maintenance
procedure to be used for the Positive Crankcase
Ventilation system.
5. State the testing procedures for each component of
the Positive Crankcase Ventilation system.
5.1 State the procedure for testing the Positive
Crankcase Ventilation Valve.
5.2 State the procedure for testing the Positive
Crankcase Ventilation Valve using the "AC" tester.
-------
104
5.4 Name the steps used to conduct the Crankcase
Vacuum Draw Test.
5.5 Name the steps required for testing the total
Positive Crankcase Ventilation system using the
-------
THERMOSTATIC AIR CLEANER
Behavioral Objectives
Upon completion of the slide series and instructor-related
teaching materials, the student will be able to:
1. Identify the process in which the thermostatic air
cleaner system reduces pollutants from the automotive
exhaust.
1.1 State how the Thermostatic Air Cleaner system
helps in reducing exhaust emissions.
1.2 Name three (3) benefits the automobile engine
derived from the Thermostatic Air Cleaner system.
1.3 Identify the process in which the thermostatic
air cleaner system reduces pollutants from the
automotive exhaust when the ambient temperature
is below 85° F.
1.4 Identify the process in which the thermostatic
air cleaner system reduces pollutants from the
automotive exhaust when ambient temperature is
above 120°F.
1.5 Identify the two types of thermostatic type air
cleaners that help control exhaust pollutants.
1.6 Identify the three operating modes of the thermo-
static air cleaner system.
2. Identify and state the purpose of each component
that comprises the thermostatic air cleaner system.
2.1 Identify and state the purpose of the air valve
door.
2.2 Identify and state the purpose of the thermostat.
2.3 Identify and state the purpose of the vacuum motor.
2.4 Identify and state the purpose of the temperature
sensor.
2.5 Identify and state the purpose of the thermostatic
air cleaner duct and shroud.
-------
106
3. Identify and state the function of each component
that comprises the Thermostatic Air Cleaner system.
3.1 Identify and state the function of the spring
on the thermostat of the Thermostatic Air Cleaner
system.
3.2 Identify the position of the air valve door in
each of the three operating modes.
3.3 Identify and state the function of the three
positions of the air bleed valve in the tempera-
ture sensor.
3.4 Identify and state the function of the shroud
and duct work of the Thermostatic Air Cleaner
system.
3.5 State the function of the vacuum motor.
4. State the inspection and maintenance procedures for
each component of the Thermostatic Air Cleaner
system.
4.1 Identify the three reasons that make inspecting
the thermostat important.
4.2 State the procedure used to inspect the vacuum
motor.
4.3 State the procedure used to inspect the temperature
sensor.
4.4 Identify the three reasons that make inspecting
the air valve door important.
4.5 State the procedure used to inspect the duct
and shroud of the Thermostatic Air Cleaner
system.
5. State the testing procedures for each component of the
Thermostatic Air Cleaner system.
5.1 Name the three steps to be taken when checking
the thermostatic air cleaner linkage.
5.2 State the procedure used to test for the three
operating modes of the Thermostatic Air Cleaner
system.
5.3 State two procedures used to test the thermostat
in the shroud of the Thermostatic Air cleaner
-------
107
Name the four steps used in testing the vacuum
motor of the Thermostatic Air Cleaner system.
Identify the procedure for testing the temperature
-------
APPENDIX H
MOTOR VEHICLE EMISSION CONTROL
-------
AIR INJECTION REACTION SYSTEM
This slide series will explain the major components and
concepts that enables the engine to reduce hydrocarbons
and carbon monoxides.
Upon completion of this slide series and instructor-related
supplementary materials, the student will be able to:
1. Identify the process in which the Air Injection
Reaction system reduces pollution from the auto-
mobile engine.
2. Identify and state the purpose of each component
that comprises the Air Injection Reaction system.
3. Identify and state the function of each component
that comprises the Air Injection Reaction system.
4. State the inspection and maintenance procedure for
the Air Injection Reaction system.
5. State the testing procedures for each component
of the Air Injection Reaction system.
-------
AIR INJECTION REACTION
NARRATIVE
Slide
101. Title
102. Different manufacturers call the air injection system
by different names but the function is the same.
American Motors calls it "Air Guard". Chrysler Cor-
poration calls it "Air Injection". Ford Motor Company
calls it "Thermactor". General Motors Corporation
calls it "AIR" or "Air Injection Reactor".
103. This slide shows a typical "Air Injection" equipped
engine with the necessary components and air delivery
plumbing to the exhaust manifold.
104. The air injection system uses an air pump as a source
of air. It also has a "diverter" or air by-pass valve
to prevent backfire in the exhaust system during
deceleration. When the engine decelerates there is
low pressure in the cylinder because the throttle
valve is closed preventing air from filling the cylinder
on the intake stroke. Under this condition the mixture
is too rich to burn in the cylinder and a raw fuel
-------
Ill
air mixture is pushed into the exhaust manifold.
If the air injection system added air to this mixture
a burn would take place in the exhaust system causing
a backfire. The diverter valve shuts air injection
off during the initial 1 to 3 seconds of deceleration
thereby preventing a backfire.
105. After the air flows through the anti-backfire valve it
flows through a hose or pipe to the check valve. The
check valve is open anytime the pressure in the air
injection system is higher than the pressure in the
exhaust system. The check valve prevents the back
flow of exhaust gas in the event of a pump failure or
during times when exhaust pressure is higher than
the air injection system pressure. After the check
valve, the air flows into the air manifold for distribu-
tion into each exhaust port near the exhaust valve.
106. The pump, air by-pass valve, check valve and injection
manifold are connected with hoses and pipes to complete
the system.
107. This shows an air injection system connected to a V-8
engine. You will notice it has an air injection
manifold for each bank of cylinders.
-------
112
outlet hose, through the diverter or by-pass valve
and connecting hose to the check valve and into the
air manifold for distribution to each exhaust valve
port.
109. The air injection system reduces carbon monoxide and
hydrocarbon emissions by injecting a flow of air into
the hot exhaust gases. This oxygen from the air pump
combines with the carbon monoxide-CO-to form C02
or carbon dioxide, a harmless gas. It also combines
with the hydrocarbons-HC-to produce I^O-or water,
usually in vapor form. Therefore, the air injection
reaction system reduces both hydrocarbons and carbon
monoxide.
110. This illustration is typical of how the belt driven
air pump is mounted on the front of the engine.
111. This illustration is a simplified view of the inside
of the air pump. The arrows show the movement of air
by the vanes through the pump. The number of vanes
vary from 2 to 5.
112. Air enters the air pump in either of two ways. One
is by an air intake filter shown here, or . . .
-------
113
The centrifugal filter is by far the most popular.
114. Output air from the pump leaves the exhaust connection
of the pump and flows into the connecting hose leading
to the diverter valve and on to the exhaust port near
the exhaust valve.
115. Maximum pressure from the pump is limited to prevent
exhaust system overheating at high speeds either by
a pressure relief valve on the pump or . . .
116. ...by the use of a combination pressure regulator diverter
valve that "dumps" excessive pump pressure to the atmosphere.
117. Two types of diverter or anti-backfire valves are used.
One type, the gulp valve, allows pump air to be sent
to the intake manifold on deceleration to dilute the
rich mixture preventing backfire. The by-pass type
valve prevents air from entering the air injection
manifold by venting the puinp air ^o atmosphere during
deceleration.
118. The gulp valve operates when intake manifold vacuum
reaches about 20-22 inches of HG. This vacuum pulls
the diaphragm down against spring force, opening the
air valve to vent pump air to the intake manifold.
-------
114
deceleration which is the critical time for backfire to
occur.
119. This picture shows a cutaway view of the diverter valve.
Parts shown are the diaphragm and spring, stem, valve
plates and manifold vacuum entrance.
120. When the engine is operating, vacuum is applied to
both sides of the diaphragm equally by means of a
timing orifice in the diaphragm. The diaphragm spring
raises the stem and unseats the upper valve plate.
121. The air flow under this condition flows in from the
pump through the diverter valve and into the exhaust
manifold or manifolds.
122. During periods of deceleration higher manifold vacuum
is imposed on the lower side of the diaphragm than on
the upper side. This vacuum forces the diaphragm
stem and valves to be moved downward.
12 3. When the stem moves down the upper valve plate seats
and the lower valve plate opens allowing the pump air
to vent to atmosphere until the vacuum on the diaphragm
becomes equal on both sides by flow through the diaphragm
-------
115
124. When the engine is turning at a high RPM excessive
pressure is produced. In the combination diverter
and pressure regulator valve, the lower valve plate is
forced down and excessive air flow is allowed to vent
to the atmosphere.
125. This illustration shows the relationship of the check
valve and air manifold.
126. This illustration shows a cutaway view of the check
valve and air flow when the system has higher pressure
than the exhaust system.
127. This view of the check valve shows the valve seated
during the time when the exhaust back pressure is higher
than the air pressure from the pump.
128. Illustrated here are the air manifolds and tubes as
used on a typical 6 and 8 cylinder engine. Usually
one tube is used for each exhaust port. On some vehicles
the manufacturers have omitted one distribution tube,
usually because of design problems.
129. In servicing the air injection system the inlet filter
element, if used, should be serviced or replaced and...
-------
116
according to the manufacturer's specifications.
131. One manufacturer recommends the pump be tested using
a special test tee and pressure gauge connected into
the outlet hose of the pump and measuring the pump
air pressure at a specified speed.
132. The gulp valve, if used, can be tested while the engine
is idling by pinching the by-pass hose shut between
the valve and the intake manifold. The idle speed
should not change. Now the vacuum sensing line should
be removed for about 5 seconds then replaced. If
the valve is functioning the engine will run rough for
about 1 to 3 seconds. Always check manufacturer's
specifications because on certain foreign models you
will damage the air pump by pinching the hose shut.
133. To test the combination diverter valve pressure regulator
hold your fingers by the vent port when the engine
idles. No air should be felt.
134. At high engine speed the by-pass and pressure relief
valve is closed and all air pressure should be delivered
to manifold.
135. Decelerating from high engine speed the throttle is
-------
117
for 1 to 3 seconds.
136. If the valve fails to function check the vacuum supply
hose from the intake manifold. At idle there should
be manifold vacuum at this point.
137. To test the check valve remove the connecting hose from
the check valve.
138. Hold your hand over the check valve with the engine
operating and feel for leakage. There should be no
air escaping.
139. When the engine is not running make sure the check
valve is not frozen shut by pushing down the check
in the valve with a screw driver, or solid rod. The
valve should move freely.
140. Last, to test for leaks with the engine operating, use
soap and water on a brush and watch for bubbles at
each connection.
-------
EXHAUST GAS RECIRCULATION SYSTEM
This slide series will explain the major components and
concepts that comprise the Exhaust Gas Recirculation
System used to control automotive exhaust emission.
Upon completion of this slide series and instructor-related
supplementary materials, the student will be able to:
1. Explain how the Exhaust Gas Recirculation system
reduces pollution from the automotive exhaust
emission.
2. Identify and state the purpose of each component
that comprises the Exhaust Gas Recirculation system.
3. Identify and state the function of each component
that comprises the Exhaust Gas Recirculation system.
4. State the inspection and maintenance procedures
for each component of the Exhaust Gas Recirculation
system.
5. State the testing procedures for each component
of the Exhaust Gas Recirculation system.
-------
EXHAUST GAS RECIRCULATION
NARRATIVE
Slide
201. Exhaust Gas Recirculation
202. EGR or the Exhaust Gas Recirculation system reduces
oxides of nitrogen emissions by recirculating regulated
amounts of exhaust gases with the air/fuel mixture
before entering the combustion chamber. As VEC is
showing us, the air/fuel mixture is diluted with
exhaust gases which reduces the combustion temperature
to restrict the formation of oxides of nitrogen.
203. VEC points out that air is approximately 23% oxygen,
75% nitrogen and 2% other harmless gases. Nitrogen
is the gas we want to control. Under atmospheric
conditions nitrogen is inert, and will not react
with other gases so it passes through the combustion
process unchanged.
204. However, above 2500°F or 1371°C when air is subjected
to hot combustion chamber temperatures and high
compression pressure, nitrogen is no longer inert.
The nitrogen combines with oxygen to form a variety
-------
120
of other gases called oxides of nitrogen, all grouped
together under the term NO^.
20 5. A function of the exhaust gas recirculation system
is to reduce combustion temperatures by reducing the
air/fuel mixture within the intake manifold with
regulated amounts of exhaust gases. These exhaust
gases will not support combustion by themselves.
This exhaust gas absorbs some of the heat of combustion
and lowers combustion temperatures, thus reducing the
formation of NO . The exhaust gas recirculation
X
system recirculates approximately 6 to 14% of the
burnt exhaust gases.
206. Exhaust gas recirculation was first used by the auto
industry in 1972 to help the internal combustion engine
meet the clean air standards. Federal Environmental
Protection Agency regulation restricts any automobile
from emitting more than 3 grams of NO per mile.
20 7. The main components of the exhaust gas recirculation
system are a flow control device called the EGR
valve and EGR-CTO switch or Exhaust Gas Recirculation-
Coolant Temperature Override switch and necessary
connecting hoses. The connecting hoses route ported
-------
121
EGR-CTO switch. This allows the Coolant Temperature
Override switch to block or unblock the vacuum source
to the EGR valve depending upon the temperature of
the engine coolant.
208. Let's take a closer look at these two components.
First, the EGR valve. It is a simple vacuum opened—
spring closed valve.
209. A coiled spring located above a flexible diaphragm
holds the valve in a normally closed position.
There's a valve vacuum nipple to accept ported vacuum
from the carburetor and a pintle which is simply a
metering rod, is connected to the diaphragm. With
no vacuum, the valve is closed. The pintle rests on
a seat at the valve bottom to prevent exhaust gas
from flowing through the valve.
210. During engine operation, ported vacuum from the
carburetor is supplied to the valve vacuum nipple.
This vacuum shown by VEC, draws the diaphragm upwards
overcoming the spring pressure and pulling the pintle
off its seat to open the valve.
211. Exhaust gas is drawn by engine intake vacuum from the
-------
122
and valve passage and into the intake manifold to be
drawn into the cylinder with the unburned gas vapors.
212. The EGR-CTO switch is the other component in the exhaust
gas recirculation system. This switch is a simple
temperature sensitive vacuum switch that allows the
vacuum to be controlled according to the engine
coolant temperature. The switch blocks vacuum to the
EGR valve to keep it closed at low temperatures.
This improves driveability during the warm-up period.
213. Proper routing of the vacuum hoses is very important
and,of course/determines the proper operation of the
system. Port 1, the upper port, is open and not
used. Port D, the center port, is connected to the
EGR valve and Port 2, the inner port, is connected to
the carburetor exhaust gas recirculation port.
Always double check for proper hose routing.
214. Some California car engines use an exhaust back
pressure sensor transducer in the exhaust gas recir-
culation system. Together with a slightly different
EGR valve, it insures maximum exhaust gas recirculation
during acceleration, and some cruising conditions.
-------
123
regulates the vacuum signal to the EGR valve through
a metal tube that connects the sensor valve and spacer.
216. This spacer is mounted between the EGR valve and the
engine.
217. The operation of the exhaust back pressure sensor
EGR valve is the same as the regular EGR valve except
the back pressure sensor is hooked between the
EGR-CTO switch and the EGR valve. One vacuum line
connects the sensor nipple, which has a calibrated
restriction, to port D of the EGR-CTO switch and
another vacuum line connects the sensor to the EGR
valve.
218. When exhaust back pressure is relatively high during
acceleration and some cruising conditions, the exhaust
back pressure traveling up the metal connecting tube
overcomes the valve diaphragm spring tension and
closes an air vent in the sensor. This allows the
carburetor ported vacuum signal to pass through the
sensor to the EGR valve resulting in exhaust gas
recirculation.
219. When exhaust back pressure is too low as during idle
-------
124
the vacuum signal is then vented to the atmosphere
and does not pass through the sensor to the EGR
valve resulting in no exhaust gas recirculation.
220. VEC is holding two different exhaust back pressure
sensors that are used on cars equipped with single
or dual exhaust systems to compensate for exhaust
back pressure differences. Be sure to check exhaust
systems and match the proper EGR valve with the
right system.
221. Some California cars equipped with the back pressure
sensor use a stainless steel restrictor plate between
the spacer and EGR valve to limit the exhaust gas
recirculation flow rate and improve driveability.
222. Many manufacturers use restrictor type orifices in
their EGR valves to limit the exhaust gas recirculation
flow rate.
223. These illustrations are a few of the various types
of exhaust gas recirculation control valve openings.
224. Prior to March 15, 1973, many manufacturers used
an ambient temperature override switch to control
-------
125
mental Protection Agency ruling stated that the ambient
temperature override switch could no longer be
used at which time manufacturers changed to the
CTO switch.
225. This illustration shows a typical ambient temperature
switch that was used before March, 1973. Some
switches do not have a filter on the vent, as shown
here.
226. This illustration shows an ambient temperature control
switch mounted on the firewall on a Chrysler product.
These ambient temperature switches were not mounted
in the same place on all automobiles.
227. Here is a CTO or coolant temperature override switch
that most automotive manufacturers adopted after March,
1973, located in the radiator, which will bleed vacuum
to atmosphere when not needed.
228. This CTO switch located in the radiator allows vacuum
to pass to the EGR valve or be blocked off, instead
of being vented to the atmosphere, dependent upon
engine coolant temperature.
-------
126
coolant passage, again to monitor the engine coolant
temperature.
230. The EGR valve may be operated by one of two sources:
carburetor ported vacuum and ported venturi vacuum
assisted by a vacuum amplifier.
231. The ported vacuum system picks up its EGR valve opera-
tion vacuum directly at a port in the carburetor throttle
body. This port is closed when the throttle is at
idle position resulting in a low vacuum supply to
the EGR valve allowing the spring to hold the valve
closed.
232. In the venturi vacuum amplified type system, the EGR
valve operating vacuum originates at the carburetor
venturi and this weak signal is then increased by the
vacuum amplifier. This amplifier then provides the
strong signal of intake manifold vacuum to operate
the EGR valve.
The vacuum amplifier is basically a balanced diaphragm-
type regulator valve. It uses the relatively low
venturi vacuum signal to control a stronger intake
-------
127
233. The exhaust gas recirculation system does not operate
at idle or at wide open throttle because of low
vacuum, so VEC does not have to work. The reason
the EGR valve does not function at these modes is
because with the exhaust gases being added to the
combustion chamber it would idle rough and would not
be able to obtain maximum performance.
234. The EGR valve uses two systems to regulate the amount
of exhaust gases going into the combustion chamber.
One method of introducing exhaust gases into the
intake manifold is the floor jet system which meters
exhaust gases through two stainless steel jets in the
intake manifold directly beneath the carburetor pri-
mary throttle bores. Intake manifold vacuum continually
draws exhaust gases through the jets but the amount
of flow depends upon the amount of vacuum, size of
the floor jets and the amount of exhaust back pressure.
235. As you can see, the EGR valve allows the exhaust
gases to reach the floor jets and enter the combustion
chamber.
236.
The other method of exhaust gas entry into the intake
manifold is the floor entry method. The difference
-------
128
does not meter the gases. You can see a cross-
sectional area of exhaust crossover section with the
EGR valve which regulates the amount of exhaust gases
entering into the intake manifold.
237. Some manufacturers used a dual diaphragm type EGR
valve to control exhaust gas flow. This valve has
two diaphragms controlled by separate vacuum sources.
One vacuum source is from the carburetor exhaust
gas recirculation port and the other from the intake
manifold. The amount of exhaust gas recirculation
is determined by the interaction of the two diaphragms.
238. Carburetor vacuum acting on one diaphragm will open
the valve. However, if high manifold vacuum is
acting on the other diaphragm such as during highway
cruise, the valve operation will be reduced and only
a small amount of exhaust gases will be recirculated.
But, during acceleration, there is little manifold
vacuum to affset the increased carburetor vacuum
and greater amounts of exhaust gases are recirculated
to help reduce NC>x formations.
239. The vacuum bias valve is also used on some 1974
vehicles. It is located between the EGR valve and
-------
129
manifold vacuum source.
240. Under relatively high manifold vacuum conditions such
as highway cruise the vacuum bias valve reduces the
amount of vacuum to the EGR valve thus reducing ex-
haust gas recirculation and preventing engine surge.
During low manifold vacuum, the vacuum bias valve
does not reduce jxhaust gas recirculation.
241. Let's see how some simple maintenance and tests car-
verify exhaust gas recirculation valve performance
or malfunction.
242. The EGR valve should be inspected or cleaned every
10,000 to 20,000 miles.
243. Diagnosing is easy. Starting with a cold engine we
will test the EGR-CTO switch.
244. After checking tne vacuum lines for leaks, restrictions
and correct routing, disconnect the vacuum line at
the EGR valve and attach a vacuum gauge to the line.
245. Then with the still cold engine, at about 2 000 rpm,
the vacuum gauge should read zero. If you get a
-------
130
must be replaced.
246. Next, increase the engine rpm until the coolant
temperature is above specified temperature. Carburetor
ported vacuum should be indicated on the vacuum gauge.
If it isn't, the exhaust gas recirculation switch
must be replaced.
247. Testing of the EGR valve is just as easy. First,
restart the engine and let it idle.
248. When the engine is at correct idle, using fingers,
push up on the exhaust gas recirculation diaphragm,
lifting the pintle off its seat. Engine rpm should
decrease and then should increase when the diaphragm
is released which indicates proper operation of the
pintle in the EGR valve. All we are doing is dumping
exhaust gas into cylinders and then blocking it off.
249. If the engine idles OK but there's no change in engine
rpms, the EGR valve or the passage to the intake manifold
may be blocked.
250. If the engine idles poorly and is not affected by
manually opening the EGR valve, you could have constant
-------
131
caused by a defective EGR valve or a defective intake
manifold.
251. To check the exhaust gas recirculation diaphragm with
vacuum, install a tee in the vacuum signal line near
the valve and connect a vacuum gauge to it.
252. Then with your fingers on the EGR valve diaphragm,
slowly accelerate the engine until you feel the
diaphragm move. Note the vacuum reading. It should
be about two or three inches of vacuum depending
upon the EGR valve being tested. Remember, do not
accelerate engine to excessive rpms trying to reach
a certain vacuum reading.
253. Continue acceleration until the diaphragm is deeply
recessed and again note the vacuum reading. It should
be between four and seven inches of vacuum depending
upon the EGR valve being tested. When testing an
EGR valve controlled by a vacuum amplifier, disconnect
the venturi vacuum signal hose at the amplifier and
connect a hand vacuum pump to the venturi hose port
on the amplifier. With the engine at normal operating
temperature and 1,000 rpms apply 2 1/2 inch vacuum
with vacuum pump to the amplifier. With your fingers
-------
132
move upward opening the EGR valve.
254. Vacuum readings should be within specifications given
in your technical service manual. If they are not
within specifications the EGR valve must be replaced.
255. The other exhaust gas recirculation test you might
have to perform would be on the California exhaust
back pressure sensor. First, inspect all exhaust gas
recirculation vacuum lines for leaks, restrictions,
and correct routing.
256. Then install a tee in the vacuum line between the
EGR valve and exhaust back pressure sensor and attach
a vacuum gauge to the tee.
257. Start the engine and let it idle. The gauge should
indicate zero vacuum.
258. Accelerate the engine to 2,000 rpms and check the
vacuum again. With coolant temperature below specified
temperature, zero vacuum should be indicated. With
coolant temperature above specified temperature,
two or three inches of vacuum should be indicated.
-------
133
make sure the vacuum was applied to the inlet side of
the sensor. Then remove the sensor and check the
exhaust tube for restrictions. Carbon or lead
deposits can be removed with a spiral wire brush.
260. If the sensor connections are OK and cleaning the
spacer exhaust tube doesn't help, replace the exhaust
back pressure sensor. It cannot be serviced.
-------
FUEL EVAPORATIVE CONTROL SYSTEM
This slide series will explain the major components and
concepts that control the fuel evaporation emissions from
the automobile.
Upon completion of this slide series and instructor-related
supplementary materials, the student will be able to:
1. Identify the process in which the Evaporative
Emission Control system reduces pollution from the
automobile engine.
2. Identify and state the purpose of each component
that comprises the Fuel Evaporative Control system.
3. Identify and state the function of each component
that comprises the Fuel Evaporative Control system.
4. State the inspection and maintenance procedures
for the Fuel Evaporative Control system.
5. State the testing procedures for each component
of the Fuel Evaporative Control system.
-------
FUEL EVAPORATIVE CONTROL
NARRATIVE
Slide
301. Title
302. It is estimated that on the pre-emission control
automobile about 20 percent of all emissions consist
of gasoline hydrocarbon vapors that evaporate from
the carburetor and fuel tank.
303. To eliminate these evaporative losses, automobile
manufacturers developed control systems beginning in
1970 for cars in California and ...
304. ... nationally in 1971, all U.S. automobile manufacturers
equipped their vehicles with the following evaporative
control devices.
305. A fuel tank safety filler cap which seals the system,
a special fuel tank designed to allow space for fuel
expansion, and a venting system to carry vapors from
the fuel tank to the carburetor air cleaner.
The venting arrangement includes a liquid check valve
-------
136
or a liquid vapor separator to keep fuel out of the
vent lines, a charcoal canister to store the vapors
and connecting lines to carry the vapor from the canister
to the carburetor air cleaner. Chrysler used a crank-
case storage system for the first two years, instead
of the canister but its function was the same.
306. The fuel evaporative emission control systems used
by most U.S. automobile manufacturers are similar,
sometimes almost identical. However, there are some
minor differences, mainly in the name. This slide
lists the names given the fuel evaporative systems
by different manufacturers:
American Motors
Chrysler
Ford
General Motors
Foreign
Fuel Tank Vapor Control
Vapor Saver
Evaporation Control System
Evaporative Emission Control
Fuel Vapor Recovery System
307. Before emission control,, fuel caps and fuel tanks
were vented to allow raw fuel vapors, or even liquid
gasoline to escape unrestricted into the atmosphere.
308. In the present fuel tank filler cap, a safety pressure
relief valve will open only if pressure from one-half
-------
137
309. If a vacuum of one-fourth to one-half inch mercury
build-up occurs, the safety vacuum relief valve will
open to let in some outside air, but normally the cap
is sealed.
310. The filler neck on most fuel tanks extends below the
top of the tank preventing the tank from being filled
100%. This provides an expansion space of 10 to
12% of tank capacity at the top to provide room for
the gasoline to expand when temperatures increase.
311. Some models, 1970 and 1971 only, use an inner expansion
tank and incorporate a fill control tube with the filler
neck. If fuel continues pumping into the tank above
the filler neck, a fill control tube returns it to the
filler neck and this either shuts off the automatic fill-
up nozzle, or tells the attendant to stop pumping.
312. With the fuel tank sealed to atmosphere, fuel vapors
will collect at the top of the tank and have only one
way to go—into the venting lines to be stored in
the charcoal canister.
313. In those tanks without internal or separate expansion
tanks, an internal expansion space must be provided
-------
138
This volume is approximately ten to twelve percent
of the fuel tank volume.
314. Some manufacturers, such as Volkswagen, use an external
expansion chamber. In operation, fuel vapors rising
from the tank are routed to the expansion chamber,
which is designed to permit the passage of fuel vapors,
but to prevent the passage of liquid fuel. From this
external chamber, the fuel vapors are carried forward
into a container filled with activated charcoal where
they are stored when the engine is not running.
315. Because most fuel tanks are flat on top, four vents
are used, one in each corner of the tank. These
are connected to a liquid vapor separator by rubber
hoses or metal pipes.
The liquid vapor separator consists of a length of
steel tubing which is mounted at an angle ahead and
.slightly above the fuel tank. This tubing holds the
four vent lines from the tank and a vent line which
leads to the charcoal canister.
These lines are of different heights so that the tank
will always be vented, regardless of vehicle attitude.
-------
139
the storage area. One vent line from the tank is
shorter than the others in order to provide a drain
back to the tank for any liquid fuel which may get
into the separator during inclined parking. The vent
to the storage area or charcoal canister is at the
highest point in the separator and has a small orifice
to minimize liquid fuel transfer to the storage area
or canister.
316. A later style liquid vapor separator is essentially
the same as the stand pipe type. The chief difference
is the mounting position, horizontal instead of vertical
due to automobile design.
317. This shows a single loop type liquid vapor separator.
The loop acts as a condenser and stand pipe, to prevent
liquid from entering the charcoal canister.
318. The compound loop vapor liquid separator operates on
a similar principle as the single loop system. The
additional loop allows for a greater amount of vapor
separation for heavy duty operation.
319. This type of separator is mounted at the top center of
the fuel tank on some models so that the internal
-------
140
adequate breathing space for the separator. It consists
of a small container filled with open-cell foam.
An opening at the bottom permits the entry of fuel
vapors from the tank. A restrictor orifice at-the
top, which is connected to a vapor tube leading to
the storage canister, permits the escape of fuel vapors,
but minimizes the chance of liquid fuel entering the
tube.
320. This system includes a three-way valve, which acts
as a stopper during fueling to prevent overfilling
the tank. This is done by closing the vapor line, thus
maintaining an expansion volume within the fuel tank.
321. During a hot-soak period (after shutting off a hot
engine) the valve opens under pressure to allow the
expanded vapors to pass into the storage canister.
322. This valve also permits air to enter the fuel tank
to relieve the vacuum created by fuel consumption or
whenever the fuel tank air pressure is reduced by a
drop in temperature.
323. The three-way valve is normally closed to retain
space in the air chamber of the fuel tank and prevents
-------
141
limits, spring pressure is overcome to permit air to
escape from the system.
32 4. On some Ford and Chrysler cars, a valve in the vent
line is normally closed during filling but opens when
excess vent pressure is present. On Chrysler the valve
is called an Overfill Limiting valve.
32 5. Another method of preventing the liquid fuel from
entering the vent line is the Liquid Check valve which
prevents the liquid from passing to the charcoal
canister. This valve is built into the tank on some
models and externally mounted on others.
The vapor inlets are at the bottom of the liquid
check valve and the outlet vent line which is connected
to the charcoal canister is at the top. To get to the
outlet, the vapors must flow past a needle valve in
the cover which is linked to a float in the bowl of
the valve.
326. If liquid enters the bowl, the float will rise and
close the needle valve, closing the vent line to the
canister. It will stay closed until the liquid drains
back into the tank.
-------
142
Vapor Storage Canister which uses activated charcoal
granules to store the vapors until they are drawn
into the carburetor. The typical canister contains
about one to one and one-half pounds of charcoal
which provides an exposed surface area of about one-
quarter square mile, enough to store almost a cup of
liquid fuel when vaporized. This storage canister
has two connections, the vent line from the fuel tank
and a connecting vent line to the carburetor air
cleaner.
328. With the engine running, outside air is drawn through
the bottom of the canister to remove fuel vapors
collected by the charcoal granules. This is called
the evacuation or purge cycle.
329. When the engine is running, and during the purge cycle,
outside air is drawn through the fiberglass filter
. at the bottom of the canister, through the carbon
granules, picking up fuel vapors and carrying them
to the air cleaner to become a part of the air-fuel
mixture to be burned.
330. This canister has 4 connections: Carburetor ported
vacuum, PCV and manifold vacuum, fuel tank vapor
-------
143
331. This shows the connections of a four-line constant
and demand purge system. The purge valve controlled
by ported vacuum allows the canister to be purged at
two different rates according to engine speed.
332. This unit is a stamped metal canister with an open
space provided at the top and bottom.
A center tube is incorporated which extends to the
bottom of the canister. Air can enter at the top of
the tube passing downward to the bottom of the canister.
The canister purge line is externally attached (by
hoses) to the carburetor air cleaner or to the PCV
valve (depending on model application).
The vapor is purged out of the canister through the
air outlet hose to the air cleaner (or PCV valve),
then through the carburetor and into the combustion
chamber—where the vapors are consumed in the normal
combustion process.
333. One method of providing additional storage space for
vapor is to vent the fuel tank to the engine crankcase
through the engine valve cover. When the engine is
started, stored vapors are drawn into the engine intake
-------
144
crankcase of stored vapor so they are ready for more
vapor storage when the engine is turned off.
334. Now let's take a look at some methods of purging the
vapor storage canister. Vapor which originated in
the fuel tank and was separated by the vapor liquid
separator is now stored in the canister. In this
system, movement of air through the canister is
caused by carburetor intake air passing over a tube
which projects into the carburetor air cleaner snorkel.
335. This creates a suction that draws the vapors out
of the canister and into the air stream entering the
snorkel. This system is known as a Variable Purge
System as it is regulated by the rate of air flow enter-
ing the air cleaner.
336. In the simplest of canister hook-ups, purging occurs
through the two vent lines from the canister to the
air cleaner. This provides a variable purge since
the amount of purging is proportional to air flow through
the air cleaner snorkel and the vacuum created inside
the air cleaner can. The tube in the snorkel purges
at high air velocity and the tube inside the filter
-------
145
337. Another purging method ties a purge line into the PCV
valve line and intake manifold vacuum. Purging air
passes to the intake manifold through a small fixed
orifice on the canister outlet. This is known as
constant purge.
338. Still another method used by some manufacturers is
called the constant and demand purge system. A
purge valve at the canister allows constant purging
at a restricted rate through an orifice until a certain
level of vacuum occurs at the canister outlet. When
ported vacuum is applied to the purge valve it allows
a higher rate of purging to take place through the
hose to intake manifold resulting in demand purging.
Demand purging is designed to ensure that purging
occurs during conditions of engine operation which will
be the least affected by purge air/fuel mixture on the
performance and driveability of the engine.
339. Prior to emission control regulation, hydrocarbons
from the carburetor bowl were allowed to escape into
the atmosphere. Advent of controls necessitated
venting of the carburetor into the canister. Here
we see one method of controlling vapors through the
-------
146
340. With the throttle in the off idle position, the anti-
perculator valve is closed. In this operational mode,
no escape of fuel vapor occurs.
341. This illustration shows the connecting hoses of the
antiperculator valve to the canister.
342. As a review, we will look at the components of the
evaporative system again: a fuel tank filler cap
which seals the system, a special fuel tank designed
to allow space for fuel expansion, and a venting
system to carry vapors from the fuel tank to the
charcoal canister and air cleaner.
The venting arrangement includes a liquid check valve
or liquid vapor separator to keep fuel out of the vent
lines, a charcoal canister to store the vapors and
connecting lines to carry the vapor from the canister
to the carburetor air cleaner.
343. Inspecting the fuel tank vapor control system begins
with checking the gasket and relief valves in the filler
cap. If the gasket has deteriorated or relief valves
are inoperative, replace the cap.
-------
147
opening and make sure all connections are tight.
Inspect liquid check valve and other parts that may
be damaged and could allow fuel vapors to escape.
A wet canister filter pad or strong smell of gasoline
under the hood may indicate a defective check valve that
could need replacing.
345. There is only one part in the system that requires
scheduled replacement and that is the filter pad at
the bottom of the charcoal canister. The filter pad
should be replaced at every 15,000 mile interval
or as recommended in the maintenance schedule.
346. Caution: On vehicles having dual fuel tanks do not
remove the filler caps of both fuel tanks during re-
fueling. When filling one tank, the filler cap
of the other tank must be left in position on the filler
neck. Removal of both filler caps during refilling could
result in fuel leakage through the vapor storage
canister due to overfilling of the fuel tanks.
34 7. This troubleshooting guide lists some of the more
common problems found in the fuel evaporative system.
348. The causes and remedies associated with -these problems
-------
POSITIVE CRANKCASE VENTILATION SYSTEM
This slide series will explain the major components and
concepts of. crankcase ventilation which enables an engine
to breathe while not contaminating the atmosphere with
by-products.
Upon completion of this slide series and instructor-related
supplementary materials, the student will be able to:
1. Identify the process in which the Crankcase Ventila-
tion system reduces pollution from the automobile
engine.
2. Identify and state the purpose of each component
that comprises the Positive Crankcase Ventilation
system.
3. Identify and state the function of each component
that comprises the Positive Crankcase Ventilation
system.
4. State the inspection and maintenance procedure
for the Positive Crankcase Ventilation system.
5. State the testing procedures for each component
of the Positive Crankcase Ventilation system.
-------
POSITIVE CRANKCASE VENTILATION
NARRATIVE
Slide
401. The crankcase ventilation system was the first anti-
pollution device installed on the automobile. This
ventilation system is known by the letters PCV which
stands for positive crankcase ventilation. The
PCV system is very dependable and efficient and
requires a minimum of maintenance.
402. The function of the positive crankcase ventilation
system is to prevent the escape of blow-by products
to the atmosphere.
403. During the combustion process higher pressures are
developed in the combustion chamber. This high
pressure results in leakage or blow-by between the
piston rings and the cylinder wall. This blow-by
occurs during the compression stroke . . .
404. "7 77'arid "during the power stroke.
405. Blow-by gases contain gasoline vapor, corrosive acids,
and water. To prevent these blow-by products from
-------
150
reacting with the engine lubrication system they have
to be removed, so the engine must be provided a
means of crankcase ventilation.
406. In pre-emission control automobiles the blow-by
products were allowed to escape to the atmosphere
through the open road draft tube. The resulting
pollution from the crankcase amounted to approximately
20% of the total pollution emitted by the automobile.
407. The earliest form of crankcase ventilation was the
road draft tube. Air passing over the end of the
tube created a partial vacuum drawing blow-by gases
from the engine crankcase.
408. There are four types of PCV systems. We have the open
system or type I which has the crankcase valve controlled
by intake manifold vacuum. The next type is type
II and the crankcase valve is controlled by the
crankcase vacuum. We have another system, type III,
that does not utilize a control valve but has a tube-
to-air cleaner device. And the last type, type IV,
is a closed system which is a combination of all
the systems.
409.
-------
151
1968 utilizes intake manifold vacuum to purge the
engine crankcase. Air is drawn through the open oil
filler cap, passing through the crankcase picking
up blow-by gases, then traveling through the PCV
valve and into the intake manifold and then into
the combustion chamber to be burned. This system
was approximately 75% efficient under heavy engine
load because of increased blow-by gases and decreased
manifold vacuum.
410. The type II system works exactly as type I except
it utilizes a West Coast control valve in place of the
PCV valve.
411. The West Coast control valve has a variable orifice
which meters crankcase gases to the intake manifold.
This variable orifice is controlled by crankcase
vacuum. Ventilating air is admitted to the crankcase
through a restricted opening in the oil filler cap.
412. The West Coast control valve at idle varies itsu
orifice opening to remove the blow-by gases according
to the flow rate created in the crankcase. At idle,
blow-by gases are drawn through an opening called
the idle groove. This groove allows constant limited
-------
152
413. At cruising speed the West Coast control valve modulator
ball is forced off of its seat by the flow rate of the
blow-by gases from the crankcase allowing these gases
to pass through the valve into the intake manifold
to be burned.
414. The type III system does not use a PCV valve or a
metered orifice. The crankcase vapors are vented
directly into the air cleaner by a slight vacuum
created by the carburetor air cleaner snorkel. No
provision was made for circulating fresh air into
the crankcase. This system has been discontinued
by American manufacturers but is still used by some
foreign car makers.
415. The type IV or closed system is used on all vehicles
built in the United States today. The closed system
does not allow blow-by gases to be emitted to the
atmosphere under any driving conditions. The blow-
by gases are consumed by either entering the intake
manifold through the PCV valve at the base of the
carburetor or through a hose from the oil filler cap
to the air cleaner and into the carburetor to be
consumed.
-------
153
type IV systems. As you can see we have a plunger
that is able to move back and forth in the valve
body controlling the air flow through the valve.
The plunger is moved by vacuum force and spring
tension. Every time the vacuum source varies the
plunger will move. This constant movement causes
the plunger and its plunger seat to become worn to
the point that it has to be replaced at regular
intervals to assure effective operation. The
PCV valve has three basic modes of operation: engine
off or backfire, high speed and idle or low speed.
417. During engine off the PCV valve plunger is pushed
to the crankcase end of valve body by the spring
tension and the absence of vacuum. In case of back-
fire, the seated plunger prevents the flame from
entering the crankcase.
418. The engine operating at low speed creates a high
intake manifold vacuum, overcoming the PCV valve
spring pressure, drawing the plunger into the valve
orifice. The PCV valve plunger position provides
a maximum restriction with a minimum blow-by gas
flow into the intake manifold.
-------
154
is low allowing the spring to move the plunger off
the seat of the intake side providing maximum flow.
Never disconnect or plug the PCV system because every
engine needs crankcase ventilation. The pressure
must be relieved one way or another.
Testing the PCV system is relatively simple. We have
the RPM Drop Test, the Vacuum Test and the Instrument
Test.
The RPM Drop Test
.1. Connect the vehicle's exhaust pipe to the shop
exhaust air system.
2. Connect an engine tachometer to the engine and
start the engine.
3. Allow engine to warm up to normal hot engine
curb idle speed and temperature; record the
engine RPM.
4. Completely restrict air flow through the PCV hose
by placing a finger over the PCV valve.
5. Record the engine RPM with the PCV system air
flow stopped.
6. An engine RPM drop of 40-80 RPM between normal
-------
155
properly functioning PCV system.
424. The Crankcase Vacuum Draw Test
425. In preparing to run the test, start the engine and
run at idle to obtain normal operating temperature.
Remove the oil filler cap and block air flow to the
crankcase from all other sources.
426. Place a sheet of thin paper over the oil filler hole.
Normal operation of the PCV system will hold the paper
against the oil filler opening, showing the presence of
crankcase vacuum.
427. The Crankcase Vacuum Draw Test Using the Inclined
Ramp and Ball Tester
1. Start engine and allow engine to run until curb
hot idle RPM is achieved.
2. Block off PCV hose leading to the air cleaner on
a closed PCV system.
3. Place the "Autolite tester" over the oil filler
opening.
4. A satisfactory crankcase vacuum draw will cause
the ball to climb into the green area.
-------
156
to climb into the red area.
6. A marginal performance of the PCV system will
result in a yellow tester reading.
Another crankcase vacuum draw tester is the AC tester.
It provides a quick and accurate method of testing
the operation of the PCV total system and the PCV
valve in separate tests.
With the engine running and the tester connected to
the oil filler hole the tester body will react to both
crankcase pressure and vacuum. Slots cut in the tester
body allow viewing of the spring loaded, color coded
drum.
These are the items found in the AC tester. Instructions
and application chart are included but most items
are self explanatory.
Using the AC dealer's Positive Crankcase Ventilation
catalog, determine the tester dial setting for the
complete system and valve testing.
Adjust the tester dial to the specified setting.
Start engine and allow engine to achieve normal hot
-------
157
432. Connect the tester assembly to the oil filler opening
using appropriate adapter. Hold the tester in a
vertical position with the hose fully extended.
Tester hose must be free of kinks and sharp bends.
433. A green color display in the tester slots indicates
a satisfactory system operation.
434. Refer to the troubleshooting chart as an aid in
diagnosing other color code indications, A red color
indicates excessive crankcase pressure cr plugged
valve ventilation. A yellow color is indicative of
low vacuum possibly from a crankcase not sealed
properly. A green color means system is satisfactory.
435. Testing the PCV Valve Alone
1. Adjust the tester to the specification for the
engine and valve being tested.
2. Start the engine and allow it to achieve normal
idle temperature and RPM.
436. 3. Connect the valve adapter to the tester hose.
4. Hold the valve adapter to the crankcase end of
the PCV valve.
437.
-------
158
the color code displayed in the tester window.
6. A green color code indicates a satisfactory valve.
If the color is not completely green, replace
the valve.
438. If a red color is showing in the slot this indicates
a plugged PCV valve or vent. A zero flow of blow-
by gases through the PCV valve will result in excessive
pressure in the crankcase. This pressure in the
crankcase may cause oil leakage from various gaskets
and seals.
439. The PCV valve plunger may become stuck in the valve
body allowing maximum air flow at idle and low speed.
As a result, the engine idles rough, caused by an
excessively lean air/fuel mixture. In addition,
excessive oil consumption may occur due to high intake
manifold vacuum and air flow impressed on the engine
crankcase.
440. The PCV valve plunger may also become stuck in the
idle position in the valve body, against manifold
end, restricting air flow during cruise and high speed
operation. This will cause excessive crankcase pressure
-------
159
441. In performing maintenance or service work, always
consult the automobile manufacturer's specifications.
While some general service rules may be formulated,
it is important that the manufacturer's maintenance
and service schedules be followed.
442. Most domestic automotive manufacturers require that
the system be inspected and the PCV valve be replaced
at 12,000 miles or 12 month intervals.
443. In addition, Ford has specific requirements for the
replacement of the inlet filter in the air cleaner . . .
444. ... and/or the cleaning of" the filter in the oil filler
cap. Again check manufacturer's specification.
44 5. When servicing the system, be sure to inspect and
clean all hoses and parts except disposable filters
and the PCV valve, which should always be replaced.
Some vehicles use a spacer block under the carburetor.
The drilled passageway in the spacer block must be
unrestricted.
446.
When replacing rubber hose used in PCV systems, be
sure to use a type of hose made for the purpose,
-------
160
447. The inlet air vent or tube from the crankcase to the
air filter, as found on AMC products, is equipped
with a filtering element or in some cases, a metal
screen and filter as indicated here. The screen
serves two functions: to filter the air before entering
the crankcase; and act as a flame arrester in the case
of backfire.
448. Some manufacturers place this type of filter, element in
the oil filler cap. Such permanent type filters
and screens are cleaned by washing them in cleaning
solvent and allowing them to drip dry.
449. One of the most popular types of filters is the
disposable type which is mounted on the inner side-
wall of the air cleaner. It is replaced at recommended
service intervals, usually 12,000 miles, except for
Ford products. The Ford Motor Co. recommends 6,000
miles as noted previously.
450. PCV valves are no longer serviceable but are simply
replaced. All valves are identified by the manufacturer's
number and in some cases, by a color code.
451. When replacing the PCV valve these variations make
-------
161
specification for the correct part application. Do
not rely on the number of the old valve since it may-
be incorrect.
452.
The PCV valve plays a vital part in maintaining
proper air/fuel ratios for best emissions reduction
-------
THERMOSTATIC AIR CLEANER SYSTEM
This slide series will explain the major components and
concepts that provides for adjustment of intake air tempera-
ture .
Upon completion of this slide series and instructor-related
supplementary materials, the student will be able to:
1. Identify the process in which the Thermostatic
Air Cleaner system reduces pollution from the
automotive engine.
2. Identify and state the purpose of each component
that comprises the Thermostatic Air Cleaner systems.
3. Identify and state the function of each component
that comprises the Thermostatic Air Cleaner
systems.
4. State the inspection and maintenance procedures
for each component of the Thermostatic Air
Cleaner systems.
5. State the testing procedures for each component
of the Thermostatic Air Cleaner systems.
-------
THERMOSTATIC AIR CLEANER
NARRATIVE
Slide
501. The "Thermostatic Air Cleaner", also known as heated
air control provides for adjustment of intake air
temperature going to the carburetor. This system
provides smoother engine operation plus . ..
502. ...Automotive manufacturers have found several benefits
by preheating the air before it enters the carburetor.
This heated air allows for better atomization of
fuel, better cold engine operation, and elimination
of carburetor icing.
503. And an overall reduction in hydrocarbons and carbon
monoxide.
504. The thermostatic air cleaner is a key device in many
auto emission control systems. Two types are widely
used; the thermostatic type ,..
505. ... and the air valve type.
506. Regardless of the type of air cleaner; air valve
-------
164
or thermostatic, its job is the jsame. And that
is to provide for adjustments of intake air temperature.
507. Each type of thermostatic air cleaner has three modes
or positions of operation, which are: the cold air
delivery mode, the regulating mode, and the hot air
delivery mode.
508. Here is a cutaway of a thermostatic air cleaner
showing the air filter, thermostat, air valve door
and snorkel for outside air. It is the function of
the thermostat acting on the air valve door which
determines whether engine compartment air, or heated
air from the shroud of the exhaust manifold is allowed
to enter the carburetor.
509. During engine start and warm-up period, the air
temperature is below approximately 105°F or 40.5°C
(this temperature will vary from each manufacturer) .
The thermostat is in a retracted position, or "hot
air mode." Since it is linked to the spring loaded
air valve it holds the valve in a closed or "heat
on position."
510. This shuts off air from the engine compartment and
-------
165
.from the heat shroud being heated by the exhaust
manifold.
511. As the manifold heated air increases to approximately
105°F or 40.5°C temperature, the thermostat begins to
extend and pulls the air valve door downward allowing
some cooler air from the engine compartment to enter
the carburetor. It is then in the "regulating mode."
512. When the temperature reaches approximately 130°F
or 54.4°C, the air valve door is fully opened to engine
compartment air, and in the "cold air mode", allowing
only engine compartment air to enter the carburetor.
5 13. Testing the thermostatic controlled air cleaner is
relatively easy.
514. First check the linkage and spring, and if they are
OK, remove the air cleaner top and remove the air
cleaner assembly from carburetor. Place the snorkel,
containing the thermostat in a pan of water with a
temperature below 105°F or 40.5°C.
515.
The thermostat should have the air valve door in the
-------
166
516. With the use of a thermometer and heat source, heat
the water to approximately 130°F or 54.4°C. The
thermostat should 'be fully extended closing the air
valve door, allowing only engine compartment air to
enter the air cleaner. Should this cold air delivery
mode not occur, replace thermostat.
517. A vacuum override motor is used on some air cleaners.
The motor is attached to the snorkel or duct and
connected to the thermostat and air valve door by
means of an override lever. This provides the control
necessary to allow full air intake during periods
of cold acceleration.
518. This is an air valve type air cleaner. It is a vacuum
operated unit. Vacuum is controlled by the temperature
sensor valve, which controls the amount of vacuum
applied to the vacuum motor that operates the damper
assembly.
519. When the temperature of the air entering the air
cleaner is about 85°F or 29.4°C or less, depending upon
specific application, the only air entering the car-
buretor, therefore, is heated air from the exhaust
manifold shroud. This is the "hot air delivery
-------
167
520. The air valve type has an air bleed valve in the temper-
ature sensor valve, and when fully closed it directs
engine vacuum to the vacuum motor, which in turn
closes the damper assembly to outside air.
521. In the regulating mode, as the temperature in the
air cleaner rises between 85°F or 29.4°C and 105°F
or 40.5°C the damper partially opens to mix outside
air with the heated air.
522. The damper opens when the air bleed valve begins to
open, bleeding off vacuum from the vacuum motor.
This weakens the vacuum signal, allowing the damper
door to partially open.
523. When the temperature in the air cleaner reaches
approximately 130°F or 54.4°C, the vacuum motor can
no longer overcome the diaphragm spring tension
holding the damper door closed. The damper door
closes and cooler engine compartment air enters the
air cleaner and carburetor. This is the "cold air
delivery mode."
524.
The high temperature causes the temperature sensor
spring to open the air bleed valve, bleeding off
-------
168
525. A low vacuum condition is also obtained during full
throttle operations, regardless of air cleaner
temperature. This is because manifold vacuum is
too weak to hold the door closed to engine compartment
air, thus the necessary volume of air required by
the wider throttle opening is available. During
engine off, or no vacuum conditions, the damper
door or valve plate blocks off the hot air duct.
This is due to the lack of vacuum at the vacuum
motor, regardless of the temperature at the sensor.
526. Testing and servicing of the air valve type air
cleaner is relatively simple.
527. Tape a thermometer in air cleaner next to temperature
sensor. Allow temperature in engine compartment
to cool to 85°F or 29.4°C or less. Install a tee
in vacuum line between vacuum motor and temperature
sensor.
528. With engine off, control damper will be open allowing
engine compartment air to enter carburetor (look into
snorkel to be sure). Install cover on air cleaner
(without wing nut) and start engine.
529.
-------
169
85°F or 29.4°C the damper door should be closed to
engine compartment air. Vacuum gauge should register
full manifold vacuum.
530. If the damper door is not closed with full vacuum,
shut off engine. Check for a binding air valve door,
disconnected linkage, a vacuum leak, or a defective
vacuum motor. A hand vacuum pump may also be used
to create full vacuum on the damper door.
531. With engine at idle and ambient temperature slightly
above 85°F or 29.4°C the damper should begin to open
to engine compartment air and should be completely
opened at approximately 130°F or 54.4°C.
532. At specified temperature the air valve door will be
wide open to engine compartment air when the engine
is idling, or the vacuum reading is 5"-9", and the
ambient temperature is between 105°F or 40.5°C-
130°F or 54.4°C.
533. When damper in snorkel begins to move toward the open
position or cold air delivery mode, quickly remove
cover on air cleaner and check thermometer next to
sensor for appropriate specified temperature, and
-------
170
5" to 9" when damper assembly is open to engine com-
partment air. You can also use a hand vacuum pump
with an attached gauge to conduct the vacuum test.
534. If temperature is within specifications and air
valve door opens to engine compartment air, system
is operating correctly.
535. If temperature is out of specifications, but vacuum
is correct, "replace the temperature sensor."
536. If both the temperature and vacuum are within specifi-
cations and air valve door remains closed to engine
compartment air, "replace vacuum motor." Remember:
temperature sensor is preset at factory, do not
adjust.
5 37. Some manufacturers use an additional air intake that
is available as an option on certain automotive
models. This thermostatic controlled air cleaner is
basically the same as the air valve we have discussed
except it has two cleaner snorkels. One snorkel
contains a vacuum motor with a temperature sensor,
which works the same as we have described. The other
snorkel contains a vacuum motor but does not have
-------
171
by intake manifold vacuum and is closed under all
conditions except wide open throttle. Testing procedure
is the same as for single snorkel.
538. The thermostatic and air valve air cleaners, when
operating properly, play a vital role in removing
-------
AIR INJECTION REACTION
Questions
T F 1. When testing the gulp valve the bypass hose is
pinched shut between the valve and intake manifold.
T F 2. When testing the air pump pressure on the left
bank of a V-8 engine equipped with an AIR system,
it is not necessary to plug the air outlet hose
feeding the right bank.
T F 3. Air is pumped from the exhaust manifold through
the diverter valve into the air pump.
T F 4. When fresh air is injected into the exhaust mani-
fold, it creates a burn to help reduce the un-
hurried hydrocarbons.
T F 5. The diverter valve and the gulp valve perform
the same end result on the engine.
6. Under normal driving conditions the check valve in the
AIR system is closed during one of the following:
a. when exhaust pressure is higher than AIR system pressure
b. when exhaust pressure is lower than air system pressure
c. when the engine is decelerating
d. a and c above
7. During deceleration the following conditions are present:
a. lower pressure in cylinder
b. richer fuel mixture
c. raw fuel air mixture in exhaust manifold
d. all of the above
8. The AIR system requires the following:
a. air pump
b. anti-backfire valve
c. air injection into the carburetor
d. a and b above
e. all of the above
-------
174
9. The main purpose of the AIR system is to:
a. cool off the exhaust gases
b. have oxygen combine with CO and HC to form C00
and H2O
c. improve gas mileage by increasing air/fuel ratio
in the cylinder
d. all of the above
10. If the air pump continues to deliver air to the exhaust
manifold during deceleration:
a. the exhaust gases would burn causing a backfire
b. the exhaust gases would become too lean to burn
c. the air pump would burn out because the diverter
valve is closed
d. a and c above
11. Which engine operation mode emits the least unburned
hydrocarbons from the exhaust system?
a. idle
b. cruise
c. deceleration
d. uphill climb
12. The purpose of the pressure relief valve or the com-
bination pressure regulator diverter valve:
a. is to increase air pressure from the air pump to
the exhaust manifold
b. is to limit the air to the exhaust manifold to
prevent exhaust system from overheating at high
speed
c. is to dump excess air pressure to the atmosphere
d. none of the above
e. b and c above
13. When decelerating the gulp valve is signaled to operate by:
a. increased manifold vacuum
b. a spring force in the gulp valve
c. a time delay mechanism of 1 to 3 seconds
d. a sudden drop in manifold vacuum
14. To test the diverter valve at engine idle speed which of
the following should result:
a. air pressure from the pump should be felt at the
vent port
b. no air pressure from the vent port should be noted
-------
175
15. Back-fire upon deceleration could indicate:
a. faulty check valves
b. faulty air pump
c. air pump belt slipping
d. faulty diverter valve
16. A customer complains he replaced the diverter valve
(By-pass valve) twice within 5,000 miles and needs
replacing again. Upon inspecting the diverter valve
you discover exhaust residue inside. A probable cause
is:
a. too low of vacuum to trigger the valve during
deceleration
b. a faulty check valve
c. low output from the air pump
d. a faulty relief valve
17. The AIR system supplies fresh air to reduce CO and
HC emission except during:
a. acceleration
b. idle
c. wide open throttle
-------
EXHAUST GAS RECIRCULATION SYSTEM
Questions
What primary pollution is reduced by adding exhaust
gases to air/fuel mixture, via the EGR system?
a. N0X
b. CO
c. HC
d. smoke
e. SA
Approximately in percent, what is the composition of
air?
a. oxygen 73 ppm, nitrogen 2 ppm, harmless gases
23 ppm
b. oxygen 23%, nitrogen 75%, other 2%
c. nitrogen 80%, other 10%, oxygen 10%
d. lead oxides 2%, oxygen 23%, nitrogen 75%
Under normal atmospheric conditions nitrogen:
a. explodes at 14.7 psi
b. is changed to a liquid at 30,000 feet
c. is an inert gas and will not react with other gases
d. all of the above
Above 2500 degrees F. or 1371 degrees C. and at high
engine compression pressure nitrogen combines with
oxygen to form what compound?
a. lead oxide
b. variety of other gases called oxides of nitrogen
- N0X
c. both of the above
d. none of above
Define these terms:
a. NO
x
b. EGR
-------
177
c. Air/fuel mixture
d. Inert
e. Oxides of nitrogen
f. EPA
The three basic components of the EGR system are:
a. EGR, CTO, and carburetor
b. CTO, carburetor, and connecting hoses
c. EGR valve, CTO switch, and connecting hoses
d. circular switch, functional valve, exhaust vent
The EGR valve will make it possible to:
a. use regular gas in high compression engine
b. use non-leaded gas in 1975 automobile
c. meter exhaust gases to the intake manifold
d. use two barrel carburetor thus increasing gas
mileage
The EGR valve operates on:
a. high temperature of gases from exhaust manifold
b. pressure from air pump
c. ported vacuum from carburetor
d. high voltage from the coil
The main purpose of the EGR-CTO switch is:
a. to electrically control the temp, of the engine
b. to control vacuum from carburetor
c. to control pressure from carburetor
d. to control vacuum from intake manifold
The main function of the EGR valve is to:
a. recirculate exhaust gases during acceleration
and deceleration
b. act as a two-way valve allowing exhaust to enter
and leave the carburetor _
c. increase air fuel ratio in the carburetor
-------
178
11. The main function of the exhaust back pressure sensor
transducer is to:
a. insure maximum exhaust gas recirculation during
acceleration and some cruising conditions
b. overcome spring pressure to control EGR valve on
California cars
c. overcome the valve spring tension and reduce
recirculation during acceleration and some
cruising condition
d. increase back pressure in California cars, thus
increasing gas mileage
12. The purpose of the spacer used with exhaust back pressure
sensor transducer is to:
a. aid in controlling exhaust gas recirculation when
low or high back pressure is present
b. allow the carburetor to be mounted off the intake
manifold
c. reduce temperature of exhaust gas going to the
CTO switch
d. increase pressure of exhaust gas going to carbure-
tor
13. The ambient temperature override switch was:
a. used on all cars sold in California after March
15, 1973
b. used in place of EGR valve before March 15, 1973
c. replaced by the CTO switch after March 15, 1973
d. used in California to increase gas mileage during
energy crises
14. The purpose for understanding the chemistry of air
is to:
a. better understand where and how some of the
emission problems evolve from the automobile
b. measure the amount of natural radiation given
off by the automobile
c. tell how much air is recylable by the automobile
d. determine if any part of the internal combustion
engine exhaust is biodegradable
T F 15. The EGR system recirculates most of the exhaust
gases during idle.
T F 16. The purpose of the vacuum amplifier is to bleed
off excess carburetor venturi to the intake
-------
179
Exhaust gases are introduced into the intake
manifold by the floor jet system, and floor
entry system.
With a cold engine at about 2000 rpm and with
a defective EGR-CTO switch the vacuum reading at
the EGR valve should be above 6 inch Hg.
Testing the EGR valve with the engine at correct
idle the engine rpm should not change when the
pintle is off its seat.
Exhaust emissions are greatest during periods
-------
FUEL EVAPORATION
Questions
The main purpose of the fuel evaporation system is
to
a. improve gas mileage
b. prevent gasoline HC vapors from escaping into the
atmosphere
c. expand gas tanks so they will hold more fuel
d. none of the above
In the present fuel tank filler cap the safety pressure
relief valve opens only
a. when the tank is being filled with fuel
b. when pressure in the fuel tank exceeds one-half
(1/2) pounds
c. when the temperature in the fuel tanks reaches
87 degrees
d. b and c above
The filler cap in the present fuel system
a. allows air into the fuel tank at all times
b. allows air into the fuel tank only when a vacuum
of over one-half (1/2) inch of mercury builds up
in the tank
c. allows air pressure to be released from the fuel
tank but is not designed to let air into the tank
d. none of the above
The fuel tanks on most cars are prevented from being
filled 100% because
a. of the expansion space of 10% to 12% designed into
the tank
b. the design of the filler neck on the fuel tank
c. of the high pressure developed in the tank during
filling
d. a and b above
The fuel vapors that come from the fuel tank that is
sealed from the atmosphere are
a. released to the atmosphere through the liquid
-------
181
check valve
b. released to the atmosphere through the charcoal
canister
c. stored in the charcoal canister until they become
part of the air/fuel mixture to be burned
d. none of the above
6. What is the reason for having the vent lines coming
from the top of the fuel tank to be of different
heights?
7. What is the purpose of the single or compound loop
vapor liquid separator?
8. What are the three purposes of the three-way valve
in the fuel evaporation system?
1.
2.
3.
9. What is the purpose of the float in the bowl located
in the liquid check valve?
10. A storage canister has two (2) connections. What are
the routings of the lines from these connections?
1.
2.
11. What would you look for in inspecting the filler
cap on a fuel tank with a vapor control system?
-------
182
2.
12. What part of the fuel evaporation system requires
scheduled replacement?
13. What is the reason for not removing the filler caps
of both fuel tanks on vehicles having dual fuel tanks?
14. Which meter on an infrared analyzer would register
a reading in detecting a fuel vapor leak?
15. Some charcoal canisters have more then two (2)
connections.
16. Demand purging of the canister only occurs when
ported vacuum is applied in a constant and
demand purge system.
17. When the purge rate is controlled by the air
flow entering the air cleaner the system is
called the variable purge system.
18. When a constant purge system is used vacuum
from the intake manifold is controlled by small
fixed orifice on the canister.
19. When demand purging is used it will result in
poor performance and driveability because of the
effect it has on the air/fuel mixture.
20. Because of the design of the auto perculation
valve it is not necessary to vent the carburetor
-------
POSITIVE CRANKCASE VENTILATION SYSTEM
Questions
On cars sold in the United States today, what type
of PCV system is used?
a. type I or open system
b. type II with West Coast
c. type III with direct vent into air cleaner
d. type IV or close system
What is the definition of PCV?
a. positive crankcase vacuum
b. potential crankcase vacuum
c. positive crankcase ventilation
d. none of the above
What percent of vehicle emission is caused by exhaust
emission?
a. 40%
b. 60%
c. 80%
d. 10%
Crankcase emission contributes what percent of the
total automotive emission output?
a. 10%
b. 20%
c. 35%
d. 60%
The type IV or closed PCV system uses the follow-
ing combination:
a. vented filler cap and open road draft tube
b. non-vented filler cap and blocked road draft tube
c. ported vacuum valve and thermostatically controlled
air cleaner
d. non-vented filler cap and hose connection from
valve cover or crankcase to air cleaner-
-------
184
6. PCV valve is the sane as:
a. positive crankcase vacuum
b. potential carbon valves
c. positive crankcase ventilation
d. all of the above
7. What was the first emission control system?
a. air injection
b. positive crankcase ventilation
c. fuel vapor control
8. Identify the three (3) main parts of the PCV valve.
9. Identify the operating modes of the PCV valve.
10. During high speed engine operation what allows the
spring to move the plunger off its seat?
11. Under what engine operation does the PCV valve offer
the greatest restriction of blow-by gas into the
intake manifold?
12. How does the PCV valve prevent flame entering the
crankcase during backfire?
13. What color on the "AC" tester indicates a satisfactory
PCV system?
14. What is the name of the valve in the crankcase ventila-
tion system?
15. What are the 3 main components of blow-by gases?
-------
185
17. What type of filter is used in the air cleaner using
the PCV system? Example: Ford Motor Co.
18. With the (type IV PCV) closed system, the only place
fresh air enters is through the
T F 19. Blow-by gases are formed mainly during the
exhaust stroke.
T F 20. In pre-emission control automobiles we did not
have the problem of blow-by gases.
T F 21. The type III system used two PCV valves, one on
each intake manifold.
T F 22. The reason the PCV valve does not need to be
replaced is because there are no moving parts.
T F 23. The PCV valve is controlled by electrical current
from the distributor.
T F 24. During the Crankcase Vacuum Draw Test you should
-------
THERMOSTATIC AIR CLEANER
Questions
What causes the air door to "close off" the snorkel
to cold air?
What causes the air door to block off heated air and
allow cold air to enter the carburetor?
If the vacuum was never allowed to the vacuum motor
in what position would the air door be in?
.In Question 3 what parts would be at fault?
Explain what causes the air bleed in the temperature
sensor to function.
Explain what happens to the air door when the tem-
perature sensor air bleed leaks vacuum constantly.
Explain what happens to the air door when the air
bleed in the temperature sensor does not bleed
vacuumi
What are the three main purposes or profits of the
thermostatic air cleaner system to the automobile?
1.
2.
3.
-------
187
Describe how the regulating mode functions on the
vacuum motor heated air system.
Describe the purpose of a vacuum override motor on
the thermostatic air cleaner.
11. When checking the thermostat in the thermostatic
air cleaner system when the temperature is above
130°F or 54.4 C the air valve door should be open
to engine compartment air.
12. The air valve door should be in the "heat on"
position or Hot Air Delivery mode when the
temperature is below 105°F or 40.5°C.
13. If damper door is not closed with full vacuum,
it could be due to a vacuum motor being defective.
14. The damper door should be completely open to
engine compartment air with the engine off and
the ambient temperature below 8 0°F.
15. Vacuum at the motor should be 5" or less when
the damper door assembly is open to engine compart-
ment air.
16. The Thermostatic Air Cleaner system's main purpose
is to reduce the formation of N0X.
17. The thermostat is in a retracted position or
"hot air mode" when temperature is below approx-
imately 105°F.
The purpose of the vacuum override motor is to provide
the necessary balance of air intake during
a. engine overheat
b. deceleration
c. cold engine drive-away
d. rapid cold acceleration
e. all of the above
The thermostatic air cleaner is in the cold air
delivery mode when
a. air temperature in the air cleaner reaches about
130°
-------
188
c. the cold override motor is denied vacuum
d. vacuum is strong enough to hold the door open
e. operating under winter conditions
20. The vacuum to the vacuum motor is obtained from
a. venturi vacuum
b. ported vacuum
c. reservoir vacuum
-------
APPENDIX J
MOTOR VEHICLE EMISSION CONTROL
-------
MOTOR VEHICLE EMISSION CONTROL
WORKSHOP REFERENCE MATERIALS
Ethyl Corporation
Central Finance Department
457 Florida Boulevard
Baton Rouge, Louisiana 70801
"The Story of Gasoline"
"Controlling Exhaust Emissions"
"Positive Crankcase Ventilation"
$ .75
.25
.25
Kal-Equip Company
Otsego, Michigan 49078
"Clean-Air Tune-Ups"
Gargano Promotions
12824 West Seven Mile Road
Detroit, Michigan 48235
313/864-4011
"Vehicle Emission Control", latest edition $3.75
Delco Remy
P.O. Box 2499
Anderson, Indiana 46011
"HEI, the High Energy Ignition System" $ .50
AC Delco Division
Power Service Training Department
P.O. Box 9000
North End Station
Detroit, Michigan
"Power Service Training Emission Control Service,"
Part I
"Power Service Training Emission Control Service,"
Part II
"Power Service Training Emission Control Service,"
Part III
$2.00 for all three parts
-------
191
Mr. Paul A. Mclntire, Jr.
14250 Plymouth Road
Detroit, Michigan 48232
313/493-2721
"What You Must Know About AMC Emission Controls",
Parts I, II, and III
Mr. C. G. Palus
P.O. Box 2119
Detroit, Michigan 48231
"Electronics Ignition System", Chrysler TMJ-106P $2.00
Mr. W. W. Howes
Parklane Towers West
One Parkland Boulevard
Dearborn, Michigan 48126
313/323-4016
"Motorcraft-Vehicle Emission Control Systems" and all
supplements. Form #AUD-7528-J $3.25
"Driveability-Basics-Emission Control Systems", Code
0901-017 $3.40
"Driveability-Solid State Ignition", 2A, Code 2302-006
$3.40
Service Section
General Motors Corporation
Detroit, Michigan 48202
"General Motors Emission Control Systems Maintenance
Manual" and all supplements. $1.40 ea.
Environmental Protection Agency
-------
APPENDIX K
MOTOR VEHICLE EMISSION CONTROL
-------
5
5
5
5
5
5
1
1
5
2
2
10
5
5
2
1
5
5
30
10
10
10
10
10
MOTOR VEHICLE EMISSION CONTROL
WORKSHOP EQUIPMENT
HC-CO analyzers
timing lights
dwell-tack
vacuum gauges
vacuum guns
pressure-volume fuel testers
oscilloscope
battery load tester (VAT 28)
continuity test lamps
volt meters- , , . ,
, . may be combined
ohm meters —J
18 inch jumper leads
3/4 inch masking tape
Chem-tool carburetor cleaner (squirt can)
R-12 Referigant
hot air blower (hot air gun)
1/4 inch shut-off valves with 1/4 inch hose fillings
1/4 inch tees with 1/4 inch hose fillings
midget screw type hose clamps
1/4 inch fuel hose
5/16 inch fuel hose
3/16 inch vacuum hose
5/32 inch vacuum hose
fender covers
box vacuum tees assortment
3/4 inch video-cassette player and monitor
35 mm slide projector and screen
audio-cassette player
overhead projector
Necessary hand tools found in auto shop.
-------
194
HAND TOOLS
1 set 7/16 thru 3/4 in. flex sockets, 3/8 drive
1 set 7/16 thru 3/4 in. 12 pt. Deepwall sockets, 3/8 drive
1 set 7/16 thru 3/4 in. 12 pt. Standard sockets, 3/8 drive
2 each ratchets, 2 in., 4 in., 6 in., 8 in., 12 in. extensions
2 each breaker bar, speed handle, universal joint
2 each 13/16 and 5/8 spark plug sockets
1 set 1/4 thru 3/4 in. comb, wrenches (open-box ends)
1 set 3/8 thru 3/4 inc. flare nut wrenches
2 each 1/2 bent dist. wrench
2 each 9/16 bent dist. wrench
1 each 4 in., 6 in., 8 in. crescent wrench
1 1/8 in. flexible dist. alien wrench
1 set alien wrenches (10 piece)
1 ignition wrench set
5 extension cord (25 ft.)
5 trouble lights
1 each 12 oz. and 16 oz. ball peen hammer
1 plastic mallet
1 each 6 in., 8 in. vise grips
1 channel locks
5 comb, pliers (6 in.)
5 needle nose pliers (6 in.)
2 Dikes (6 in.)
1 battery service kit (pliers, post cleaner
terminal puller thydrometer)
5 remote starter switches
-------
195
2 Stubby standard blade screwdrivers
2 Stubby phillips (No. 2) screwdrivers
5 4 in. standard blade screwdrivers
5 4 in. phillips (No. 2) screwdrivers
5 6 in. standard blade screwdrivers
2 small pencil screwdrivers
2 10 in. standard blade screwdrivers
2 flexible idle misture adjusting screwdrivers
1 set flat feeler gauges (standard and nonmagnetic)
2 sets wire gaping gauge (spark plug gaping tool)
Chalk for timing marks
Rags
Golf tees (vacuum line plugs)
1 universal float gauge measuring tool
1 universal float pin gauge set or number drill index (1 thru 60)
2 insulated secondary wire pliers
1 compression tester
1 telescoping magnet (12 in. to 24 in.)
1 small pocket magnet
1 roll black electrical tape
1 assortment solderless connector kit (optional)
1 tube dist. cam lubricant
-------
196
Shop Facilities Exhaust system
Exhaust system hoses and adapters for
both single and dual exhaust
Battery charger
Safety glasses, goggles, faceshields
Air compressor hoses and blow guns
Two-ton floor jack
-------
APPENDIX L
MOTOR VEHICLE EMISSION CONTROL
-------
NONDISPERSIVE INFRARED ANALYZER
The infrared exhaust gas analyzer operates on the principle
of absorption of specific wavelengths of infrared energy by
carbon monoxide and hydrocarbon gases present in the sample
of automotive exhaust gases. In general, the system compares
the infrared waves that have been passed through a reference
cell to the infrared waves that have been passed through
a sample cell filled with automotive exhaust gases. Because
the hydrocarbons and carbon monoxide molecules absorb the
infrared waves in the sample cell, but not the reference
cell, the difference in the amount of infrared energy
absorbed is detected by an optical detector. An electrical
signal from the optical detector is sent to the amplifier,
modified and read out on the hydrocarbon and carbon monoxide
meters.
Analyzer Components
The infrared source is a heater which emits constant infra-
red waves through the reference and sample cells to the
filters and detectors.
The chopper is a segmented wheel, used to interrupt the
infrared waves at regular intervals to create a pulsating
infrared signal.
-------
199
A reference cell is a tube containing an inert gas which
the infrared waves are passed through to the detector un-
changed.
The sample cell is a flow-through tube which receives a
sample of exhaust gas through which infrared waves are
passed through to the detector. The hydrocarbons and
carbon monoxide molecules in the exhaust gas absorb some
of the waves before reaching the detector.
The filter is a device used to exclude all but those infra-
red wavelengths that hydrocarbons and carbon monoxide
molecules can absorb.
The detector receives the infrared waves that were allowed
to pass through the filters and changes these waves to
electrical signals. The signals from the detector are
used to calculate the hydrocarbons and carbon monoxide
content of the exhaust gas sample.
The amplifier receives the signal from the detectors and
through electronic circuitry sends a signal to the meters which
gives a visual reading.
Operation Principles
As stated before, the analyzer operates on the principle of,
absorption of specific wavelengths of infrared waves. The
source of the infrared waves is a metal shielded heat
-------
200
energy waves through the reference and sample cells. The
type of analyzer will determine if it has one or two infra-
red wave sources. If it has only one source the infrared
waves will be reflected off a mirror and divided to provide
an infrared source for both of the cells. If it has two
infrared sources there will be one energy source for each
cell.
The constant spectrum of infrared waves is interrupted by
a rotating segmented chopper disc. This interruption of
the flow of infrared waves creates a pulsating AC signal.
This signal is then amplified and rectified to a DC signal
which is used to activate the meters.
The reference cell is a closed tube containing an inert
gas or a gas that is very low in absorption of infrared
waves. This gas will be used as a reference or standard
that measures the amount of energy or waves initiated by
the infrared wave source.
The sample cell is a flow-through tube which receives
a metered amount of exhaust gas to be analyzed. As the gas
passes through the cell the hydrocarbons and carbon monoxide
molecules in the exhaust gas sample will absorb a certain
amount of the infrared waves. The amount of infrared waves
-------
201
and carbon monoxide in the sample tube.
The infrared waves passing through the reference and sample
cells pass through a filter which excludes all of the
infrared waves 'except those which can be absorbed by hydro-
carbons and carbon monoxide molecules. After the infrared
waves pass through the filter they are received by the
optical detectors. There are two detectors for each cell:
a detector for the wavelength that measures hydrocarbons
and a detector for the wavelength that measures carbon
monoxide. These detectors convert the pulsating infrared
waves to electrical signals. The difference between the
absorption of the infrared waves in the reference cell and
the sample cell is converted to electrical signals. These
signals are then sent to the amplifier circuitry where
they are amplified and changed into direct current used
to operate the hydrocarbon and carbon monoxide meters.
The meters indicate the concentration of hydrocarbons and
carbon monoxide in the metered amount of exhaust gas in
the sample cell. This concentration is converted to read
as parts per million for hydrocarbon and percentage for
carbon monoxide.
Copies of the above presentation may be obtained from the
Department of Industrial Sciences, Colorado State University,
-------
APPENDIX M
MOTOR VEHICLE EMISSION CONTROL
CHEMISTRY OF THE INTERNAL COMBUSTION
-------
CHEMISTRY OF THE INTERNAL COMBUSTION ENGINE NARRATIVE
The internal combustion engine is a machine for releasing
the chemical energy stored in the fuel, through the process
of combustion, and converting some of that energy into
motion. Unfortunately, a great deal of that energy is
wasted in the form of heat, or waste gases, or worn rubber.
It is important to realize that the engine is a complete
system; this would include, for example, the fuel, air,
lubrication, mechanical parts and all the products of
combustion. What goes into the engine determines how
well it operates. How well the engine operates determines,
to some extent, what comes out of the engine: the emissions.
Now the concern about air pollution caused by engines has led
to certain restraints being placed on the kinds of things
that can be wasted from an engine: the emissions. These
restraints have a great influence on both the engine
efficiency and on the type of fuel that must be used. The
goal is to achieve the most efficiency consistent with a
cheap and plentiful fuel and harmless emissions. I am
going to try to explain how the chemistry of the fuel,
the combustion processes that occur inside the engine, and
emissions control determine how close we can come to that
goal with our current technology.
A fuel gasoline contains literally hundreds of chemicals,
by far the major proportion of which are called hydrocarbons.
-------
204
The typical hydrocarbons in gasoline may be N-petane,
2-methyl-butane and benzene. These are long chemical names
for the kinds of structures you see here, and, as you can
see, these hydrocarbons are called hydrocarbons because
they contain only atoms of hydrogen and atoms of carbon.
These compounds can be divided into three groups for the
purposes of discussion of the chemistry of the internal
combustion engine. We can divide them into straight-chain
hydrocarbons, branched-chain hydrocarbons and ring hydro-
carbons. Sometimes these ring hydrocarbons are called
aromatic hydrocarbons. It is the energy stored in the
chemical bond in the hydrocarbons that is released when the
hydrocarbons burn in oxygen inside the cylinder in the
internal combustion engine. As you all know, the efficiency
of an engine is partly dependent upon the compression ratio.
For knock-free performance in a particular engine, the
octane rating of a fuel must be correct. The octane rating
that is needed for knock-free operation increases as the
compression ratio increases, as shown here. For example,
at a compression ratio of 4:1, the octane number needed is
about 60. For a compression ratio which is very high such
as 12:1, an octane number is 102. The octane rating is a
number given to the fuel, based on the comparison of the
performance of a standard engine, the so-called CFR engine
(which is really only a variable compression ratio engine),
-------
205
running on a mixture of two hydrocarbons. The first one
is called N-heptane and it is a straight-chain hydrocarbon
and has an octane number assigned to it of 0. Also, there
is another hydrocarbon called 224 trimethylpentane. Some-
times this is called iso-octane; as you can see, this is a
branched-chain hydrocarbon and has an octane number of 100.
In fact, generally hydrocarbons which are straight-chain
hydrocarbons have low octane numbers and branched and ring
hydrocarbons have fairly high octane numbers. We shall see
why this is later on when we get into a discussion of the
chemistry of the processes occurring inside the cylinder
during each of the strokes in an auto engine. The octane
number can be significantly increased by adding small
amounts of certain additives to gasoline. One of these
additives is called tetra-ethyl lead. This is the so-called
anti-knock additive in a gasoline. The tetra-ethyl lead
is called that because there are 4 ethyl groups (1, 2, 3, 4)
in the chemical together with an atom of lead to which the
4 ethyl groups are attached. We can characterize the lead
tetra-ethyl in this way. Usually there are about 2 to 5
grams of this material added to the gasoline in order to
raise the octane number.
Lead compounds must eventually be removed from the engine;
otherwise it would tend to fill up with these kinds of
-------
206
may lead to severe problems with some types of emissions
control.
Generally speaking, there are many other additives in small
amounts in gasoline for a variety of purposes. They can
be added as detergents to keep the engine clean. They
can be deposit modifiers, anti-icing agents, anti-rust
agents and dyes, etc. Again, it is very important to under-
stand that what goes into the engine must come out in some
form or another, even if that particular chemical does not
perform any useful function in the engine. For example,
in gasolines there are impurities, sulphur and phosphorus
compounds which are in the original crude oil and rather
difficult to remove. These compounds are not useful,
and they may form certain substances inside the engine
which may cause alarm and may cause air pollution, which
we shall see later.
Obviously, a gasoline must be mixed with air before it will
burn. Air consists of approximately 20% oxygen and about
80% nitrogen. There are small amounts of other things like
water vapor and carbon dioxide but those won't concern us
for the moment. The hydrocarbons that we've been talking
about in the fuel react only with the oxygen during the
burning processes, but the nitrogen in the air is extremely
-------
207
pollutants. The ratio of the amount of air to fuel, the
so-called AF ratio, is very important. It plays a critical
role in the miles per gallon that can be achieved and the
power that can be achieved in the internal combustion engine
and also in the types and the amounts of the various emissions
that come out of the engine. Theoretically, about 14.5 to
15 pounds are needed to burn one pound of gasoline. This
air-fuel ratio is quite close to that which gives maximum
fuel economy. This correct amount, or as it is called,
stoichiometric amount, is calculated from the overall chemical
reaction that corresponds to the complete reaction of all
the fuel hydrocarbons with just the right amount of oxygen.
Unfortunately, maximum power is achieved with a richer
mixture, as you can see on this diagram.
I hope you can already see that fuel and air-fuel character-
istics play an important part in determining the economy,
power, and the emissions that are delivered by the internal
combustion engine. In a short while we will see how the
chemistry of the combustion process provides an explanation
of the power and the problems of the internal combustion
engine.
The chemistry of the combustion processes that occur in the
four-stroke or auto cycle engine may be illustrated by con-
-------
208
during each stroke. In the intake stroke, the complex mixture
consisting of all the chemicals contained in the gasoline
and the air is pulled into the cylinder. We have oxygen
molecules, nitrogen molecules, straight-chain hydrocarbons,
branched and ring hydrocarbons, and the additives that are
contained in the gasoline. You must bear in mind that the
air-fuel ratio has already been determined by the carburetor.
As the piston moves up during the compression stroke, the
volume is rapidly decreased. As this volume decreases,
the pressure increases tremendously and the temperature
begins to increase greatly. This has the same effect as
that produced when pumping up a bicycle tire with a hand pump.
The pump barrel gets very warm. This is because the air
is being compressed inside the barrel of the pump. As
the temperature increases in the compression stroke, the
straight-chain hydrocarbons have a tendency to begin to
burn before the other types of hydrocarbons. If the anti-
knock additive was not present, it would burn too fast
(spontaneous ignition) and too early (pre-flame reactions).
This burning without the spark having fired would result
in the mixture exploding rather than burning smoothly.
These explosions set up shock waves which strike the cylinders
and piston and cause a characteristic knocking or pinging
sound. The released energy that we have gotten from burning
the hydrocarbons would be completely wasted. The anti-knock
-------
209
The tetra-ethyl lead breaks up and forms four ethyl
groups and lead groups. The lead then combines with the
decomposing straight-chain hydrocarbons and forms sub-
stances which do not burn as rapidly as the straight-chain
hydrocarbons themselves. So the combustion is retarded or
slowed down until the stroke reaches the top; the spark
plug fires and the whole mixture begins to burn in a
controlled manner.
In the power stroke the spark plug is fired and all of the
hydrocarbons begin to combust or burn. The straight-chain
hydrocarbons with the lead attached begin to burn. The
branched-chain hydrocarbons begin to burn, and to react
with the oxygen. The ring hydrocarbons begin to react with
the oxygen, all three types of hydrocarbons from carbon
dioxide, water, and heat. The tremendous increase in temp-
erature results and the heat expands the gases inside the
cylinder and the piston is pushed down. Unfortunately,
there are several side effects which occur here that are
partly due to the high temperature inside the cylinder and
partly due to the nature of the fuel. The lead compounds that
we talked about earlier, the anti-knock additives, have
now done their job and the scavenging agents which are
included in the gasoline specifically to remove the lead
compounds at this point do so by reacting with the lead to
-------
210
which are lead chloride, lead bromide, and lead bromo-
chloride. At the high temperature the nitrogen also begins
to combine with the oxygen. Now this is a reaction that
does not normally occur. It only occurs in this instance
because of the very high temperature generated inside the
cylinder. Although not very much of the nitrogen reacts
with the oxygen, enough does to cause some severe problems,
as we shall see later. It forms a chemical compound called
nitric oxide, the chemical formula being NO. The high
temperature can also lead to some unusual chemical changes
in the ring hydrocarbons that are contained in the gasoline.
The ring hydrocarbons can stick together, or they can fuse
to form strange-looking chemicals, one example of which
is called benzopyrene. The burning of the hydrocarbons
is also never quite complete for very many complex reasons.
One reason is that the air fuel ratio that is normally
used in engines is too rich. We talked a little about
this earlier. One of the reasons for a mixture that is too
rich being used is that the maximum power can be achieved
with this kind of mixture, whereas for fuel economy you
would use the stoichiometric amount. Because the mixture
is too rich, there is not quite enough oxygen available
for burning all the hydrocarbons. Therefore, we get
what is called incomplete combustion, and there are some
hydrocarbons left over. This incomplete combustion process
-------
211
instead of carbon dioxide. Finally, there is an effect
known as quenching which leaves some of the hydrocarbons
unburned. This occurs because the area at the edge of the
cylinder and the piston is metal and this conducts away
the heat. These parts of the cylinder are a little bit
cooler than the inside part. This means that the combustion
process does not occur completely and it leaves unburned
hydrocarbons.
In the exhaust stroke, which is the next stroke, the hot,
very complex mixture of materials and waste goes out through
the manifold and into the tailpipe. We are talking about
things like the following: unburned hydrocarbons, used
hydrocarbons, such as benzopyrene, carbon monoxide,
carbon dioxide, nitric oxide, lead compounds of various
types, nitrogen which has not been used, water and waste
heat. In the next part, we shall see how these exhaust
gases or emissions produce air pollution and what can be
done to remove some of these problems.
The gases that are emitted from the tailpipe cool rapidly
and are now diluted because they are present in the air and
the gases are surrounded by oxygen and nitrogen which are
the two major constituents of the air. Further chemical
reactions can go on as the gases are exposed to more oxygen,
-------
212
compound word which was originally coined in England
as being smoke plus fog. The cooling allows some of the
nitric oxide to react with oxygen to form something called
nitrogen dioxide. Nitrogen dioxide is a brown, very highly
toxic gas. The combination of NO and NC^ is sometimes
referred to as N0x« The nitrogen dioxide is an unusual gas
in that when sunlight falls on it, it can break up into
nitric oxide again and an oxygen atom. The chemical formula
for this is 0. Now this is very different from the normal
oxygen gas that you find in air. That has a chemical formula
of 02• The nitric oxide that is formed in this particular
chemical reaction can then recycle and the whole process
can come about again and we can form more oxygen atoms
with the formula of 0. These 0 atoms are extremely reactive
and they are looking for things to take off on; and one of
the things that they can react with rather nicely is oxygen
molecules; that is exactly what happens. Oxygen atoms
react with oxygen molecules: 0 + gives 0^ which is
called ozone. This is one of the gases in smog which causes
the eyes to sting. It causes also the breakdown of rubber
and plastics and various other things. For example, it can
attack furnishings in plastics, etc. Ozone may also attack
plants and produce degradation. There are further reactions
which go on. The ozone, 0^, may react with some of the
unburned hydrocarbons that we talked about in the earlier
section to give some complicated chemicals given the abbrevi-
-------
213
peroxy acetyl nitrate. These PANs are also toxic to animals
and plants.
Carbon monoxide that is formed from incomplete combustion
is also very dangerous to health in that when it is inhaled
in sufficient quantities, it can react with the blood
proteins instead of oxygen, and it can produce symptoms
of sleepiness and nausea. If the concentrations of this
chemical, carbon monoxide, are very high, it can even cause
death.
The lead compounds which are exhausted as gases originally—
remember they react with the scavengers, which were there
deliberately to remove them from the engine--now cool, and
instead of gases they can form particles in the atmosphere.
Sometimes these are called aerosols. The lead compounds
may also be dangerous to health. There are many studies now
underway trying to find out if the lead compounds are
indeed harmful to health. Finally, there is a great deal
of concern now about the fused or rearranged hydrocarbons.
These are known; in fact, many of them are known to be car-
cinogenic. This means they can be cancer-producing. One
of the examples which I gave earlier of a fused hydrocarbon
was benzopyrene and this is known to be a cancer-producing
chemical. As you can see, there are some reasonable concerns
about the health problems that may be encountered from
-------
214
It has been recognized that the automobile is responsible
for the major portion of the tonnage of air pollutants, and
it is now thought that the automobile is responsible for
approximately 60-70% of the total air pollution tonnage. This
has lead to the 1970 ammendments to the Clean Air Act. These
ammendments mandate drastic reductions in the air pollutants,
carbon monoxide, hydrocarbons, and N0X emitted by automobiles
and require that they be made by the 1975 and 1976 model
years. You can see the drastic reduction from 10 to 0.4
in hydrocarbons, from 80 to 3.4 in carbon monoxide, and from
4 to .4 in NO . These 1975 standards were extended one
A
year to 1976 models and the 1976 standards were extended
to 1977. Very recently, because of problems that were being
encountered in the emission control technology, they were
extended to 1978.
Problems in the development of emissions control technology
led to requests, as I just mentioned, to delay these standards.
But for most 19 75 automobiles, the manufacturers have chosen
to use exhaust gas recirculation (EGR) and catalytic con-
verters as the two main types of devices for controlling
hydrocarbons, carbon monoxide and NO emission.
A
Catalytic converters will be placed before the muffler, as
close as possible to the engine manifold on the exhaust pipe.
-------
215
one is a palladium-platinum mixture which is deposited onto
an inert support, sometimes alumina. This support may be
in the form of pellets, approximately 3/8 inch diameter, or
it may be in the form of a solid honeycomb, sometimes called
a monolith. The palladium and platinum compounds are
catalysts. These are chemicals which make chemical reactions
go much more easily. The chemical reaction which we want
to make go much more easily is the further burning of
carbon monoxide and unburned hydrocarbons. The job of the
catalyst is to make sure that the unburned hydrocarbons in
carbon monoxide are completely burned to harmless carbon
dioxide and water. Unfortunately, again, there are problems
.with such converters. One of the major problems is that
they are poisoned by the lead compounds which we now know
are included as anti-knock additives. These lead compounds
which are coming out of the manifold coat the surface of
the catalyst and stop the catalyst from being efficient at
changing carbon monoxide and hydrocarbons into carbon
dioxide and water. The ones that are included on the 19 75
models are called oxidative catalysts and do not remove one
of the principal sources of smog, which is the N0„, as we
A
said earlier. Finally, and this may turn out to be a
severe problem, are any sulphur compounds which may be
impurities in the original gasoline and can be nicely burned
by the catalytic converter. The sulphur burns with oxygen
to become sulphur dioxide. The sulphur dioxide can react
-------
216
trioxide may react with water vapor in the atmosphere to
form sulphuric acid. Sulphuric acid is a rather obnoxious
substance. It is very useful when it is present in the
battery; that is, battery acid. When it comes out the
tailpipe it can be extremely harmful. Recent tests have
shown that catalytic converters do indeed extensively increase
the amount of sulphuric acid coming out of the automobile.
The only way in which the sulphur problem can be solved
is for the gasoline itself to be made purer with respect
to the sulphur. The sulphur is removed from the gasoline.
Unfortunately, that route is rather expensive because that
can only be done in the refinery, and the refining techniques
need to be changed rather radically in order to remove the
sulphur completely.
The problem of the lead may be resolved; in fact, it has
been resolved for 19 75 cars which have converters by using
lead-free gasoline. In most 19 75 autos there will be a
special gas tank inlet which will only be fitted by small
nozzles on pumps which are pumping lead-free gas. I
mentioned previously that TEL or tetra-ethyl lead was added
to increase the octane number of the fuel. If the TEL
is removed, the current method of maintaining the octane
number is to change refining techniques. In fact, one of
the ways in which you can increase the octane rating of the
-------
217
increase the amount of ring or aeromatic hydrocarbons in the
gasoline, as much as up to 40% of the gasoline. Remember,
the ring hydrocarbons have much higher octane in general
than the straight-chain or branched-chain hydrocarbons.
The NO problem is still unsolved and much research is
X
now underway to try to design another type of converter
which will be placed probably before the oxidative converter
to remove NO . although the technology for this is not
at present economically viable. It seems that the only
way to achieve clean air and more miles to the gallon
may be to use other fuels. For example, one fuel is propane.
There are already conversion kits available on the market
for this kind of fuel. Hydrogen could be used, or even
perhaps electricity in an electric car. I guess another
way to try to do this is to completely redesign the power
train and use stratified engines, turbines or steam engines.
It certainly is going to be an interesting and a difficult
challenge for the auto engineer and the mechanics of the
future.
Copies of the above presentation may be obtained from the
Department of Industrial Sciences, Colorado State University,
-------
APPENDIX N
-------
EMISSION SYSTEM EVALUATION
Evaluator —________________________ Address _________________________________
Series ABODE Showing Time _____________________
PleaBe evaluate each of the following categories:
1. Illustrations low 12 3 4 5 high
2. Narrations low 12 3 4 5 high
3. Clarity of content low 12 3 4 5 high
4. Logical progression low 1 2 3 4 5 high
5. Terminology low 1 2 3 4 5 high
Slide Key: Place an I for Illustration and an N for Narration in the appropriate box.
E ¦ Excellent A ¦ Acceptable P = Poor Please feel free to make comments.
Slide
#
E
A
P
Comments
Slide
#
E
A
P
Comments
1
32
2
33
3
34
4
35
5
36
6
37
7
38
8
39
9
40
10
41
11
42
12
43
13
44
14
45
15
46
16
47
17
48
18
49
19
50
20
51
21
52
22
53
23
54
24
55
25
56
26
57
27
58
28
59
29
60
30
61
31
-------
220
AIR INJECTION REACTION SYSTEM EVALUATION
Low 1
2
3
4
5 High
Illustrations
1
2
15
Narration
1
2
1
14
Clarity of
Content
1
1
1
15
Logical
Progression
4
14
Terminology
3
1
14
EXHAUST GAS RECIRCULATION SYSTEM EVALUATION
Low 1
2
3
4
5 High
Illustrations
1
1
1
15
Narration
1
3
14
Clarity of
Content
1
1
2
14
Logical
Progression
1
3
1
13
Terminology
2
2
-------
221
POSITIVE CRANKCASE VENTILATION SYSTEM EVALUATION
Low 1
2
3
4
5 High
Illustrations
2
2
14
Narration
2
1
15
Clarity of
Content
1
3
1
13
Logical
Progression
1
1
2
14
Terminology
2
1
2
13
FUEL EVAPORATIVE SYSTEM EVALUATION
Low 1
2
3
4
5 High
Illustrations
1
2
2
13
Narration
1
3
3
11
Clarity of
Content
1
1
2
14
Logical
Progression
4
2
12
Terminology
2
1
2
-------
222
THERMOSTATIC AIR CLEANER SYSTEM EVALUATION
Low 1
2
3
4
5 High
Illustrations
1
2
15
Narration
2
2
14
Clarity of
Content
1
2
15
Logical
Progression
1
1
2
14
Terminology
1
1
1
-------
APPENDIX 0
EMISSIONS I AND II COURSE OUTLINE
-------
IS 4 88 AUTO EMISSIONS CONTROL I
I. Introduction
A. Pre-Test
B. Air Pollution
1. HC, CO, NO : Defined and Explained
a. Effects on Human, Plant, and Animal
Life
b. Air Quality: Visible vs. Invisible
Film: "New Rules of the Road"
c. Discuss Film
C. Define: Denver Air Quality Control Region -
counties include Denver, Jefferson, Arapahoe,
Adams, Boulder, Douglas, Gilpin and Clear Creek
1. Progress to Date and Your Future Involvement
a. Pilot Programs at A.T.L. Health
Department Involvement and CSU Programs
1) Federal Standards Must Be Met
According to Federal Clean Air
Act. An Attempt to Improve Air
Quality Must Be Made
a) Probable Involvement of Schools
and Instructors
2) Proposed Mandatory Vehicle Emissions
Inspection
a) Training - Personnel
b) Stations - Equipment
c) Vehicles - 19 68 and Newer
(1) Exempt Vehicles
II. Ignition: Pre-Test
A. Film: "M.M. Introduction to Emissions"
B. Review Formation and Causes of HC, CO, N0X From
Engines
C. Pre-Controlled Systems
1. Theory and Purpose of Ignition System
a. Basic Electricity
1. Volts, Amps, Ohms
b. Components: Construction and Operatio.n
c. Diagnostic Procedure in Locating Problem
D. Modified Ignition Controls
1. Ignition Effects on Emissions
a. HC, CO, N0X
-------
225
b. Advance Controls
1) Dual Diaphragms
2) Electric Solenoids Controlling
Vacuum Supply
3) Modified Advance Curves
E. Electronic Ignition
1. Purpose and Advantages
2. Theory of Operation
a. Component Identification (General)
3. Specific Manufacturers
a. Chrysler
b. GM
c. Ford
Film: "Emissions In Perspective"
Carburetion
A. Pre-Controlled
1. Carburetion Principles
a. Pressure and Effects
b. Carburetor Circuits
1. Jetting and Power
c. Air Cleaners
d. Fuel System Demands
1) Fuel Pressure and
e. Diagnostic Procedure
B. Carburetor Modifications
1. Idle Mixture Limiters
2. Idle Stop Limiters
3. Combination Valves (C.E.C.)
a. Decel Valves
4. Carburetor Vacuum Principles
a. Manifold
b. Ported
c. Venturi
5. Venting
6. Adjustments and Service
a. Idle Mixture
b. Float
7. Chokes
a. Vacuum Breaks
b. Water Heated
c. Electric
d. Staged
8. Exhaust Restrictions and Controls
a. Heat Riser
b. Restrictor Pipes
c. Exhaust System Problems
Engine Modifications
M.M. Film: Engine Modification Systems
Valves
-------
226
A. Cam Shafts
1. Overlap Variations
B. Valves, Ports, and Valve Arrangement
C. Intake Manifolds
1. Heat Ribs
2. Water Heated
3. Cross Over Passage
D. Exhaust Manifolds
1. Flow Design
2. Scavenging
E. Combustion Chambers
1. Reduction of Quench Area
a. Contoured Shape
b. Closer Parts Mating
c. Piston Ring Placement
d. Compression Ratios
1) Heads
2) Effects on Combustion Temperature
3) Temperature Effects on Emissions
F. Engine Operating Temperature
1. Operating Temperature Changes
2. Effects.of Pressure Caps on System
V. Positive Crankcase Ventilation (PCV)
A. Principle and Purpose of Crankcase Ventilation
M.M. Film: "O.C.V."
B. Types of Ventilation Control
1. Type 1: Open-Valve controlled by intake
manifold vacuum.
2. Type 2: Open-Valve controlled by crank-
case vacuum.
3. Type 3: Open-Tube to Air Cleaner
4. Type 4: Closed-Combination System
C.S.U. Slides: "P.C.V."
5. Correct P.C.V. Valve Application
C. Lab Experience: Effects of P.C.V. on Emissions
HC-CO Readings with Correct, Plugged and Open
P.C.V. Valves
VI. Thermostatic Air Cleaners
A. Principle and Purpose of T.A.C.
1. Better Cold Operation Driveability
-------
227
3. Reduction of Emissions HC and CO
Slides: C.S.U. - "T.A.C."
M.M. - "T.A.C."
VII. Air Injection Systems
Slides: C.S.U. and M.M.
A. System Components
1. Pump Design and Operation
2. Air Delivery Plumbing and Check Valves
3. Pressure Relief Valves
4. Routing of Air Delivery by Use of Diverter
Valve
a. Diverter Valve Operation
b. Vacuum Signals to Diverter Valve
Generated by Driving Modes
Lab Experience: Effects of A.I.R. HC-CO
Analyzer Readings with A.I.R. Functioning
and Then Disconnected.
VIII. Fuel Evaporative System
Slides: C.S.U. and M.M.
A. Fuel Tanks
1. Tank Expansion Space
2. Filler Neck Location Limiting Overfill
3. Tank Venting
4. Caps: No Vent and Pressure Relief
B. Liquid Vapor Separators
1. Tube-Type
2. Separator with Float
C. Fuel Lines
1. Routing and Construction
2. In Line Valves (GM Check Valve)
a. Overfill Valves
b. 3-way Combination Valves (Ford)
D. Vapor Storage
1. Crankcase
a. Purging
2. Carbon Canister
a. Construction and Purpose
b. Connections and Location
c. Purge Methods
1. Variable
2. Constant
3. Combination Constant-Demand
3. Carburetor Bowl Venting
a. Carburetor Vent Valve
-------
228
Transmission and Speed Controlled Spark (TCS and SCS)
A. Purpose, Similarity and Differences by
Manufacturers
1. Reduction of HC, CO, NO
2. The Necessity of Manuals and Specifications
B. Ignition Timing Controls
1.
Temperature Switches (Ambient and Ccolant)
2.
Transmission Switches
3.
Ported Vacuum
4.
Speed Sensors (In Cable)
a. Amplifier Modules
5.
Solenoids
6.
Time Relays
7.
Spark Delay Valves (Vacuum)
8.
Distributor Vacuum Advance Control Valve
(Deceleration)
C. American Motors System
Slides: M.M.
1. Spark Control Systems
a. TCS
D. General Motors System
Slides: M.M.
1. Spark Control Systems
a. TCS
b. CEC
c. SCS
E. Chrysler System
1. Spark Control Systems
a. CAP
b. CAS
c. Distributor Solenoid Retard and Advance
d. TCS Control
1. Solenoid Vacuum Valve
F. Ford System
Slides: M.M.
1. Spark Control Systems
Film: Ford ESC
a. ESC System
Film: Ford TRS
b. TRS System
1) Dual Diaphragm Distributor
c. Spark Delay Valves (Restrictors)
d. PVS Valve: Distributor Vacuum Control
1) Overheat Protection
-------
229
A. Purpose and Principles
1. Reduce N0X
2. Reduce Combustion Temperature
Slides: C.S.U. and M.M.
B. EGR Controls
1. Exhaust Recycle Requirements vs. Engine
Operating Modes
2. Floor Jets
3. Vacuum Signal Operation of EGR
a. Cold Override
b. Idle
c. Wide Open Throttle
d. Vacuum Amplifier
XI. Catalytic Converters
A. Construction and Chemical Principle
1. Pellet
2. Monolith
3. Precautions Due to Converter
a. Shielding
b. Insulation
c. Heat
d. Damage Due To:
1) Fuel
2) Heat
3) Moisture
4) Road Hazard
Film: "Eleven Together"
XII. Exhaust Analyzer
A. Principles of Operation
1. Infra-Red Light
2. Optical Benches
B. Pre-Testing Preparations
1. Engine at Normal Operating Temperature
2. Correct Calibration and Span
3. Proper "Hook-Up"
4. Additional Uses
C. Care
1. Filters
2. Water Traps
3. Volume of Air Flow (Vacuum Gauge)
-------
IS 488 AUTO EMISSIONS CONTROL II
I. Orientation - set up procedures
A. Analyzer and diagnostic equipment usage
1. Infrared analyzer
2. Diagnostic equipment
B. Ignition and fuel system troubleshooting
1. Adjustments:
a. Check and adjust ignition to manufacturer
"specs".
b. Check and adjust fuel system to manufacturer
"specs".
1) Choke assembly and choke assists
2) Solenoids and CEC valves
3) Adjust air-fuel mixture and idle speed
II. Positive crankcase ventilation system checks and service
A. Crankcase vacuum draw test
B. Hose routing
C. Comparison vacuum test
1. PCV system normal vs. RCV system plugged and open
D. Correct PCV valve application
III. Thermostatic air cleaners
A. Thermostatic type
1. Air door operation and proper closing and
opening temperature
a. Proper vacuum override operation
B. Vacuum motor type
1. Hose routing and vacuum source
2. Proper air door operation
-------
231
3. Vacuum motor check
4. Temperature sensor checks to factory "specs".
IV. Air injection systems
A. Pump drive belt tension
1. Pump output and hose connections
2. Check valve operation
3. Pressure relief valve check
4. Diverter valve operation
V. Fuel evaporative system
A. Hose routing—purge and vapor lines
B. Leak detection with infrared analyzer
C. Canister and hose damage
D. Canister filter
E. Fuel tank cap inspection
VI. Distributor advance control systems
A. Vacuum hose routing and connections
B. Vacuum control solenoids
C. Electrical circuits and components
1. Ambient temperature switches
2. Coolant temperature switches
3. Vacuum delay valve check
D. Correct operation at manufacturers specified road
speed or gear
VII. Exhaust gas recirculation
A. Hose routing and connections
-------
232
1. Vacuum source within "specs"
2. Proper CTO switch operation
C. Vacuum amplified system
1. Amplifier operation within manufacturer "specs".
-------
APPENDIX P
-------
PRE-TEST IGNITION AND CARBURETION
True-False: If the statement is true circle T
If the statement is false circle F
T F 1. The drift of electrons between atoms of a conductor
is referred to as current flow.
T F 2. Electron drift through a conductor is from
negative to positive.
T F 3. Magnetic lines of force form a complete circuit
from north to south.
T F 4. Current passing through a wire creates a magnetic
field.
T F 5. The magnetic effect of an electromagnet is
decreased when it becomes hot.
T F 6. Increasing the current in a coil winding will
increase the magnetic strength of the coil.
T F 7. Voltage across the. circuit is the difference in
electrical pressure between the two sides of
a circuit.
T F 8. When the voltage of a circuit is increased
the resistance is also increased.
T F 9. Resistance in a circuit is effective only when
current flows.
T F 10. Voltage is generated in a conductor by moving
the conductor through a stationary magnetic field.
T F 11. Current is generated in a conductor when magnetic
lines of force are cut by the conductor.
T F 12. The breakdown of the magnetic field in a coil
causes secondary ignition operation.
T F 13. Point dwell in the distributor is a measurement
of the time that the ignition points are open.
T . F 14. The flow of current in the primary windings of
an ignition coil depends upon the capacity of
the condenser.
T F 15. Ignition spark occurs at just the instant the
distributor breaker points close.
-------
235
T F 16. In an ignition distributor, the condenser is
connected in series with the breaker points.
T F 17. In the fuel pump the gasoline enters on one
side of the diaphragm and leaves on the other.
T F 18. A hole in the float will cause the fuel mixture
to become lean.
T F 19. A hole in the fuel pump diaphragm will be noticed
because fuel will leak from the bottom of the
fuel pump.
T F 20. A vacuum could be considered a negative air pressure.
T F 21. The fuel must move through the main discharge
tube in order to reach the power valve.
T F 22. The power circuit is actuated by an increase
in vacuum.
T F 23. The transfer port discharges fuel only after
the throttle plate moves from the idle position.
T F 24. To replace the ignition coil on the Delco HEI,
you must replace the distributor cap too.
T F 25. Gap between pickup and reluctor on Chrysler
cars can be checked with ordinary feeler gauges.
Multiple Choice: Circle the letter in front of the most
correct answer.
26. As engine speed increases under acceleration, manifold
vacuum:
a. decreases
b. remains constant
c. drops
d. none of above
27. The transistor module on the Delco High Energy Ignition
system is located:
a. near the radiator to keep it cool
b. in the distributor
c. on firewall because it has a heat sink around it
d. hung in open air because it does not need a ground
-------
236
28. Following the air flow through the venturi, the throttle
plate would be located:
a. before the venturi
b. after the venturi
c. in the intake manifold
29. The purpose of the accelerator pump is to:
a. pump fuel into the float chamber
b. aid the fuel pump at idle speeds
c. filter out impurities from the gas tank
d. give immediate response for throttle demands
for increased power
30. An external ceramic dual resistor is used on:
a. Chrysler cars only
b. Ford and Chrysler products
c. only import cars that come to U.S.A. to be sold
d. GM cars sold in South America
31. Idle speed adjustments should be made while:
a. engine is cold and operating
b. engine is warm and operating
c. engine is cold and off
d. engine is warm and off
32. Elimination of breaker points by transistor ignition
extends life:
a. of ignition timing adjustment
b. of ignition switch
c. of the exhaust system because it has less of a
problem of backfiring
d. of antenna because radio problems are cut down
33. The reluctor is Chrysler's term for the part that
replaces the distributor cam. Ford calls it:
a. armature
b. impulse trigger
c. pole pick up unit
d. the rotor
34. If the float was stuck in the up position, the other
systems would:
a. receive too much fuel
b. receive no or little fuel
c. work to compensate for the float system
-------
237
35. The circuits or circuit that would be operating at
part throttle would be:
a. the idle circuit
b. the idle and low speed circuit
c. the low speed and power circuit
36. Oil, dirt, or oxidation on the breaker points causes
poor ignition because it:
a. increases primary current
b. increases resistance in secondary
c. decreases primary current
37. Condenser plates are charged as:
a. breaker points are just opening
b. breaker points are in contact
c. breaker points are just closing
38. If the gap between pickup coil and reluctor is too
great:
a. ignition timing will be overadvanced
b. pickup may not trigger the control unit, causing
misfire
c.. reluctor will burn out
d. pole pickup gets too cold
39. When you disconnect part of the transistor ignition
harness, Ford recommends that you:
a. coat terminals with electrically-conductive
grease
b. wipe terminals to remove any oil or grease
c. any H2O repelling oil
d. just a good grease
40. The distributor rotor carries:
a. battery current
b. primary current
c. secondary current
41. Sharp corners on the spark plug electrodes cause the
plug to fire at:
a. the lowest voltage
b. the highest voltage
-------
238
42. The centrifugal advance mechanism advances ignition
timing by turning the:
a. cam with rotation
b. cam against rotation
c. breaker points in direction of rotation
d. breaker points against direction of rotation
43. The higher ignition voltage requirements are at:
a. high speed full throttle acceleration
b. low speed part throttle acceleration
c. high speed part throttle
44. The transistor control units on most transistor ignition
systems can be serviced by:
a. installation of circuit board and transistors kit
b. replacement of complete unit only
c. running the alternator backwards
d. make the internal combustion engine misfire
45. An inverted wave form on an oscilloscope screen
indicates:
a. cracked distributor cap
b. vehicle polarity reversed
c. coil on backwards
-------
APPENDIX Q
-------
VEHICLE EMISSION SYSTEMS CONTROL EXAMINATION
Name Date
Directions: Select the best choice of those given for each
question and circle its corresponding letter.
1. The average available secondary voltage at the coil in an
electronic ignition system is:
a. 15 KV
b. 25 KV
c. 35 KV
d. 55 KV
2. In a dual diaphragm vacuum advance unit the diaphragm
chamber closest to the distributor housing must have:
a. vacuum only at wide open throttle
b. vacuum only during deceleration
c. vacuum only when transmission switch is closed
d. full vacuum at idle
3. If point dwell changes from 27 degree dwell to 35 degree
dwell on a V-8 engine the effect on timing and HC emissions
at idle will be:
a. timing advanced and HC increased
b. timing advanced and HC decreased
c. timing retarded and HC increased
d. timing retarded and HC decreased
4. Although vacuum controlled, the early fuel evaporative
valve works similar to the .
a. heat riser
b. EGR valve
c. staged choke pull off
d. idle speed solenoid
5. When would the EGR valve be in operation?
a. When the engine is at normal temperature and 2 ,000 RPM
b. When the engine is at normal temperature and at idle
c. When the engine is cold and at 2,000 RPM
d. When the engine is cold and the transmission is in
1st or 2nd gear
-------
241
6. The vacuum differential valve (VDV) used on some 1975
Ford vehicles is part of the system.
a • EGR
b. TAC
c. Thermactor
d. Spark control
7. The fuel evaporative system consists of four (4) major
components:
a. Fuel tank, pressure-vacuum fuel tank cap, liquid
vapor separator, diverter valve.
b. Pressure-vacuum fuel tank cap, vapor canister, liquid
vapor separator, fuel tank.
c. Liquid vapor separator, thermal vacuum valve, third
speed solenoid, coolant temperature sensor.
d. Fuel pump, carburetor, fuel tank, pressure vacuum
fuel tank cap.
8. The purpose of the Chrysler OSAC valve is to:
a. eliminate spark advance at low speeds
b. delay spark advance during deceleration
c. delay spark advance under all conditions
d. delay spark advance on acceleration
9. The TIC valve on Chrysler vehicles operates to:
a. provide full vacuum advance at low ambient temperatures
b. provide no vacuum advance at high ambient temperatures
c. provide vacuum advance at high coolant temperatures
d. provide full advance during high speed operation
10. The transmission controlled spark system is used to help
reduce exhaust emissions by:
a. Advancing the spark with the transmission in low gear
b. Providing a hotter spark with the transmission in
high gear
c. Retarding the spark with the transmission in lower
gears and the engine at operating temperature
11. The speed controlled spark system serves the same purpose
as the transmission controlled spark. However, unlike the
TCS system the spark is controlled by a:
a. Transmission switch
b. Speed sensor and amplifier
c. Temperature switch
-------
242
12. If you are checking your exhaust emissions at 2,000 RPM
in neutral and you get a high KC reading, one possible
cause could be:
a. Inoperative vacuum advance unit
b. Float level too low
c. Idle mixture screw set too rich
13. One purpose of a check valve in the AIR system is to
prevent:
a. Excess pump pressure in the system
b. Excessive vacuum in the system
c. Damage to system due to pump belt failure
14. If ignition timing is advanced 5 degrees over specifi-
cations you will read an increase in with the infrared
analyzer.
a. Carbon monoxide
b. Hydrocarbon
c. Oxides of nitrogen
d. Carbon
15. What is the purpose of the exhaust gas recirculation?
a. Lowers peak flame temperatures during combustion
b. Controls manifold crossover flow
c. Controls flow of exhaust through the converter
16. The speed sensor in a spark control system is used to_
a. Operate tach
b. Operate solenoid vacuum control valve
c. Energize buzzer for over speeding
d. Prevents premature upshift of transmission
17. The air pump introduces fresh air into the to
reduce hydrocarbon and carbon monoxide emissions.
a. Engine exhaust system
b. Intake ports
c. EGR
d. TCS
18. The air pump is a
type of pump,
a.
b.
c.
d.
Gear
Impeller
Vane
-------
243
19. The charcoal canister filter should be at
regular intervals.
a. Cleaned
b. Replaced
c. Blown out with compressed air
d. Turned over
20. Back-fire upon deceleration could indicate:
a. Faulty check valves
b. Faulty air pump
c. Air pump belt slipping
d. Faulty diverter valve
21;. On a vehicle with a heated air intake system, the air
door should be in the at idle with.:
a cold engine.
a. Hot air delivery mode
b. Cold air delivery mode
c. Regulating mode
22. A defective (stuck open) E.G.R. valve will cause:
a. Hard starting
b. Rough idle
c. High speed miss
d. High NO emissions
X
23. On most vehicles equipped with an automatic transmission
and transmission controlled spark (TCS), you can check
operation of the TCS system by putting the transmission
in:
a. Park
b. Reverse
c. Neutral
d. Any drive range
24. An engine "diesels" or "runs" after the ignition switch
is turned off. This is most often caused by:
a. Overheated engine
b. Too lean A/F ratio
c. Idling too fast at shut down
25. You have adjusted the idle mixture screws using a
tachometer only and obtained a satisfactory smooth
idle. When you check the exhaust emissions with a
HCrCO meter you discover HC-CO readings above "specs".
-------
244
a. One mixture needle too lean and one too rich
b. Both needles too rich
c. Both needles too lean
d. Either a or b of the above
26. A solenoid that holds the throttle plates slightly-
open and at the same time controls distributor vacuum
is called the:
a. Idle stop solenoid
b. TPS solenoid
c. VCS solenoid
d. CEC solenoid
27. Replacing main metering jets with leaner ones may:
a. Raise gas mileage
b. Lower gas mileage
c. May do either of the above
28. When the diverter valve, used on air injection systems,
diverts air to the atmosphere it is triggered into
action by:
a. A sudden drop in manifold vacuum
b. High manifold vacuum
c. Exhaust gas pressure
d. The air pump
29. A choke vacuum brake failure will be noticed:
a. On a fully warm engine
b. On cold engine drive-away
c. When trying to start flooded cold engines
30. Exhaust temperatures are hottest if:
a. Timing is advanced more than specs
b. Set right on specs
c. Timing is retarded more than specs
31. Idle CO reading too high indicate:
a. Mixture too lean
b. Mixture too rich
c. Timing too advanced
d. a and c
32. No distributor vacuum advance at 2500 RPM would:
a. Tend to lower KC readings
b. Tend to raise HC readings
-------
245
33. HC readings are highest on:
a. Acceleration
b. Deceleration
c. Approximately the same in a or b
34. A cracked intake manifold causing an air leak would tend
to:
a. Lower HC readings
b. Raise HC readings
c. Raise CO readings
d. Both a and c
35. 2500 RPM CO readings too high indicate:
a. Mixture too rich
b. Timing too advanced
c. Both a and b
d. None of the above
36. If the HC and CO read too high at idle but OK at 2500
RPM:
a. The idle mixture screws are set too rich
b. The initial timing is set too far advanced
c. The initial timing is retarded too much
d. Both a and c
37. When adjusting idle mixtures leaner you may lower CO
too much and see:
a. CO start climbing higher again
b. HC start climbing higher again
c. Both a and b
d. None of the above
38. If the power circuit is "open" when you test at 2500
RPM the CO readings will be:
a. Higher than normal
b. Lower than normal
c. Will not be shown on CO meter
39. The TCS system reduced unburned hydrocarbons and carbon
monoxide in the exhaust by:
a. Eliminating vacuum spark advance when the engine is
cold
b. Eliminating vacuum spark advance in low gear ranges
at normal engine operating temperatures
c. Filters the exhaust through a carbon canister
-------
246
40. To check the speed controlled spark (SCS) system a
mechanic must do which of the following:
a. Raise the rear wheels
b. Shift to DRIVE
c. Note engine timing when advancing speed from below
38 mph to above
d. All of the above
41. The AIR system supplies fresh air to the exhaust gases
except during:
a. Acceleration
b. Idle
c. Wide open throttle
d. Deceleration
42. The TCS system includes a thermal vacuum hot override
switch whose function is:
a. To allow advance in high gear only
b. To allow unrestricted vacuum advance
c. To recover coolant during boilover
d. To allow for better driveability during cold operation
43. NO in measurable quantities is formed in the combustion
chamber when temperatures reach approximately "
degrees F. and above.
a. 1500
b. 1800
c. 2500
d. 3500
44. The purpose of Ford's vacuum override motor on the air
cleaner is to provide the necessary balance of air
intake during:
a. Cold engine drive-away
b. Rapid cold acceleration
c. Engine overheat
-------
247
Matching
Directions:
45.
46,
47.
48.
Match the correct emission system name or component
on the right with the description at the left.
Place the letter on the line provided by the
number.
A component of the fuel evaporative
emission control system that prevents
liquid fuel from entering the vapor line
to the canister.
Regulates the amount of crankcase
gases flowing from the engine crankcase
to the carburetor as determined by intake
manifold vacuum.
A valve in the air injection system
that dumps air into the atmosphere on
deceleration.
A system designed to keep air
entering the carburetor at approximately
100° F. when underhood temperatures are
less than 100^ F.
A.
CCS System
B.
EGR Valve
C.
Temperature
Override Switch
D.
Diverter Valve
E.
TCS System
F.
AIR System
G.
Separator,
Liquid/Vapor
H.
PCV Valve
I.
SCS System
J.
Separator,
Purge/Vapor
Completion
49. A system designed to prevent fuel vapors from the fuel
tank and carburetor from escaping into the atmosphere is
called the .
50. Most E.G.R. valves begin to open when to inches
-------
APPENDIX R
-------
249
COLORADO TEACHER EMISSIONS CLASS SURVEY
1. Instructor
2. Location
3. School
4. Number of MVEC workshops held ,
5. Average length, in hours, of MVEC classes
6. How was class offered: separate section integrated
7. Types of participants: students mechanics non-mech.
teachers
8. Number of participants in all classes: mechanics students
non-mech. teachers
9. Number of planned MVEC workshops and duration: a) Spring hrs.
b) Summer hrs . c) Fall hrs. d) Winter hrs.
10. Separate emissions section integrated .
11. Type of participants for planned classes: mechanics
students teachers
12. When will class be offered: day night
13. Do you need more training to conduct additional MVEC classes?
PCV , AIR , Fuel Evap. , EGR , TAC , Spark Control ,
Conv. , Therm. React. .
14. What instructional materials have you used?
GM , Ford , Chrysler , AMC , Echlin , Gargano ,
Mitchell Manuals , Other
15. What type of student do you prefer to train?
mechanic H. S. student other
16. What type of student is most receptive to the materials?
-------
APPENDIX S
MOTOR VEHICLE EMISSION CONTROL
-------
EMISSIONS PRE/POST-TEST
Name Date
Directions: Please circle the letter in front of the correct response.
Some questions will have more "RIGHT" answers than those given, circle the
best choice of those given.
1. Black smoke from a vehicle tail pipe indicates the engine is burning
oil.
A. True
B. False
2. An engine "diesels" or "runs" after the ignition switch is turned off.
This is most often caused by:
A. Overheated engine
B. Too lean
C. Idling too fast at shut down
3. You have adjusted the idle mixture screws using a tachometer only and
obtained a satisfactory smooth idle. When you check the exhaust
emissions with a HC-CO meter you discover HC-CO readings out of
"specs." The problem could be:
A. One mixture needle too lean and one too rich
B. Both needles too rich
C. Both needles too lean
D. All of the above
E. None of the above
4. You have worked on both a 1962 and 1972 model cars today. After both
owners left you discovered the reaiator caps got mixed up. Of you were
concerned only with the danger of possible overheating which owner
would you call back?
A. Owner of 1962 model
B. Owner of 1972 model
D. Neither owner because neither car would overheat
5. You are driving in subzero temperature at 50 MPH. Suddenly the
heater blows cool air and the engine boils. The trouble is:
A. Radiator froze while driving
B. Thermostat stuck closed while driving
C. Waterpump stopped pumping while driving
-------
252
Emissions Page 2
6. EGR is used to:
A. Reduce HC-CO
B. Reduce N0x
C. Increase gas mileage
7. Not enough "Float Drop" will probably cause trouble when:
A. Starting a warm engine
B. Idling a warm engine
C. Driving at high speed with wide open throttle
D. Cruising on level road at 25 MPH
8. Two owners with identical cars are going together on a trip. Owner A
is towing a 16' travel trailer. Owner B will tow nothing. Both
engines need vacuum diaphrams in their distributors but you only have
one. Considering only GAS MILEAGE so less combined fuel is burned by
these two cars on this trip, which owner should get the new distributor
diaphram?
A. Owner towing trailer
B. Makes no difference
C. Owner not towing
9. If ignition specs are: initial timing 0°, total advance 25°, mechanical
advance 10°, how many degrees is vacuum advance?
A. 15°
B. 35°
C. 30
10. A "dash pot" failure will be noticed:
A. On acceleration
B. On starting engine
C. On deceleration
11. You change the dwell on an engine from 30 to 26. What effect does this
have on timing?
A. No change
B. Advance it
C. Retards it
12. An engine with this firing order, 14283675, which cylinder besides #1
will flash a timing light so you can see the marks?
A. 8
B. 5
C. 3
-------
253
Emissions Page 3
13. CEC solenoids and idle stop solenoids both hold the throttle plates
slightly open. Which one also controls the distributor vacuum?
A. CEC solenoid
B. Idle stop solenoid
14. Replacing main metering jets with leaner ones may:
A. Raise gas mileage
B. Lower gas mileage
C. May do either of the above
15. You are cruising at 50 MPH on a level road. Your manifold vacuum gauge
reads 14". Which carburetor circuit is not operating?
A. Float circuit
B. High speed circuit
C. Power circuit
16. When the divertor valve, used on air injection systems, diverts air to
the atmosphere it is triggered into action by:
A. A sudden drop in manifold vacuum
B. High manifold vacuum
C. Exhaust gas pressure
D. The air pump
17. Spark plugs that missfire because of "Bridging" one or two days after
a tune up are an indication of:
A. Owner's bad driving habits
B. Poor qulaity spark plugs
C. Heavy combustion chamber deposits
18. The owner knows he has: (a) one open plug wire, (b) a weak coil,
(c) high float level, (d) no vacuum advance in the distributor. He
will pay to fix only one of these problems.
1. Which one would you fix if he only wants lower HC emissions?
A B C D
2. Which one would you fix if he only wants lower CO emissions?
A B C D
3. Which one would you fix if he can't start it cold?
-------
254
Emissions Page 4
19. To perform a cylinder compression test you:
A. Remove all spark plugs and test
B. Leave all spark plugs in and test
C. Remove one spark plug at a time and test
D. On a V-8 remove one bank at a time and test
20. A choke vacuum brake failure will be noticed:
A. On a fully warm engine
B. On cold engine drive-away
C. When trying to start flooded cold engines
21. When manifold vacuum is 16" but venturi and spark port vacuum are 0",
the engine is:
A. Stopped
B. Running at 2500 RPM in neutral
C. Idling
22. You suspect one flat lobe on the cam shaft. Which diagnosis test
would you use to further support your suspicion?
A. Compression test
B. Cylinder leakage test
C. Cylinder balance test
23. A cranking vacuum test is done with:
A. All spark plugs in
B. All spark plugs out
C. One spark plug out at a time
24. Exhaust temperatures are hottest if:
A. Timing is advanced more than specs
B. Set right on specs
C. Retarded less than specs
25. PCV valves are used to:
A. Control HC emissions
B. Ventilate the crankcase
C. Both of the above
D. None of the above
26. Idle CO reading too high indicate:
A. Mixture too lean
B. Mixture too rich
C. Timing too advanced
-------
255
Emissions Page 5
27. Power valve circuits are normally:
A. Closed at idle
B. Open at idle
C. Neither of the above
28. No distributor vacuum advance at 2500 RPM would:
A. Tend to lower HC readings
B. Tend to raise HC readings
C. Probably not be noticeable on HC scale
29. The "fuel level" setting and the "float level" setting are the same
measurement.
A. True
B. False
30. HC readings are highest on:
A. Acceleration
B. Deceleration
C. Approximately the same in A or B
31. NOx emissions are reduced by:
A. Evaporative control systems
B. EGR control systems
C. Carbon canisters
D. Spark delay valve
32. Crankcase fumes are 100% controlled by:
A. Open PCV systems
B. Closed PCV systems
C. Road draft tube
33. A.I.R. control, thermal reactor and catalytic convertor systems all reduce
HC and CO after the exhaust leaves the engine cylinder.
A. True
B. False
34. A cracked intake manifold causing an air leak would tend to:
A. Lower HC readings
B. Raise HC readings
C. Raise CO readings
-------
256
Emissions Page 6
35. 2500 RPM CO readings too high indicate:
A. Mixture too rich
B. Timing too advanced
C. Both A and B
D. None of the above
36. Vapor lock is caused by:
A. Using gasoline of the wrong octane number
B. Too much heat on the fuel pump and lines
C. Too much fuel pump pressure
37. If the HC and CO read too high at idle but OK at 2500 RPM:
A. The idle mixture screws are set too rich
B. The initial timing is set too far advanced
C. The initial timing is retarded too much
D. Both A and C
38. The fuel vapors stored in a carbon canister:
A. Are returned to the gas tank when the engine is started
B. Are burned in the engine when it is started
C. Stored in canister until saturated and then replaced
39. On an engine that is normally denied vacuum advance at idle you
discover full manifold vacuum at the advance unit. With this condition
you would:
A. See higher HC readings than normal
B. See higher CO readings than normal
C. See lower HC readings than normal
D. Both A and B
40. When an engine missfires you would expect:
A. To see very high CO and HC readings
B. To see only very high HC readings
C. To see only very high CO readings
D. No appreciable change in either reading
41. Air leaks in the muffler or tail pipe will:
A. Make idle HC-CO read lower than it should
B. Make idle HC-CO read higher than it should
C. Affect only HC reading
D. Affect only CO reading
42. Heated carburetor air is necessary on emissions controlled engines because:
A. Of the altered advance curve
B. Of the retarded timing used
C. Of the leaner carburetor mixture used
-------
257
Emissions Page 7
43. When adjusting idle mixtures leaner, you may lower CO too much and see:
A. CO start climbing higher again
B. HC start climbing higher again
C. Both A and B
D. None of the above
44. If you advance initial timing it will:
A. Increase idle RPM
B. Decrease idle RPM
C. Have no effect on RPM
45. If the power circuit is "open" when you test at 2500 RPM the CO readings
will be:
A. Higher than normal
B. Lower than normal
C. Will not be shown on CO meter
46. What causes photochemical smog:
A. Unburned hydrocarbons and oxides of nitrogen mixed with vapor and air
B. Unburned hydrocarbons and oxides of nitrogen mixed with air in the
presence of sunlight
47. The thermostatic air cleaner (heated air intake system) aids the:
A. Control of blow-by gases
B. Vacuum spark control
C. Atomization of fuel
D. Evaporative control system
48. When intake manifold vacuum is applied at idle to the retard diaphragm
on an engine equipped with a dual diaphragm distributor the breaker plate:
A. Moves opposite to distributor rotation
B. Moves in the same direction as distributor rotation
C. Does not move
D. May move in either direction depending on amount of vacuum
49. On what two strokes do most of the hydrocarbons reach the crankcase:
A. Intake and exhaust
B. Compression and combustion
C. Exhaust and power
D. Power and intake
50. Comparing pre-1961 against 1974-75 models with factory installed emission
devices, what percentage of exhaust hydrocarbons are reduced?
A. 50%
B. 30%
C. 70%
-------
APPENDIX T
PROPOSED CRITERIA, QUALIFICATIONS, AND
PROCEDURES FOR INSPECTORS AND STATE
-------
PROPOSED
CRITERIA, QUALIFICATIONS, AND PROCEDURES
FOR
INSPECTORS AND STATE INVESTIGATORS
CERTIFICATION
Submitted to
State of Colorado
Department of Health
Air Pollution Control Commission
Prepared by
Colorado State University
Industrial Sciences Department
-------
PROPOSED CRITERIA, QUALIFICATIONS, AND PROCEDURES
FOR
INSPECTORS AND STATE INVESTIGATORS CERTIFICATION
FORWARD
Through legislation in 1955 the United States Congress authorized
a Federal program (PL 84-159) of air pollution research and
technical assistance to state and local governments. This
legislation established a policy, retained in all subsequent
legislation, of giving state and local governments the fundamental
responsibility for controlling local air pollution with the
Federal government providing leadership and support. Although
the establishment of motor vehicle emissions standards are a
Federal responsibility, the states are responsible for controlling,
regulating, or restricting the use, operation, or movement
of licensed motor vehicles.
The General Assembly of the State of Colorado enacted Senate
Bill #393 directing the Colorado Air Pollution Control Commission
to establish a Motor Vehicle Emission Control Program. This
document delineates the qualifications and requirements of the
state inspector and investigator pursuant to Section 66-31-28
of the Act. Section 66-31-28 of the Act authorized by the Commission
pursuant to Section 13-5-113 of the Colorado Revised Stacutes,
requires all state employed investigators shall complete a
training course and pass qualification test as developed and
-------
261
approved by the Commission as related to the orientation and
basic maintenance procedures on air pollution controls systems
installed by manufacturers. Only inspectors passing said
qualification test shall perform emission inspection. Pursuant
to Section 66-31-28 (4) (a) of the Act, said qualification
test will be used by the Departments of Health and Revenue to
insure competency for consumer protection in the implementation
of the motor vehicle emissions control program. Paragraph two
of Section 66-31-28 states the Departments of Health and Revenue
shall jointly recommend additional training programs necessary
to help implement motor vehicle emission control measures.
The need for trained personnel in the automotive industry, whether
it be repairman, investigator, or inspector, has been borne out
by many studies. Before an inspection and maintenance program
can sucessfully become operational it is imperative an adequate
supply of trained inspectors, investigators and maintenance
mechanics be available.
CONTENTS
Section 1.0 General Provisions
Section 2.0 Introduction
Section 3.0 Criteria for Certification of Inspectors
Section 4.0 Criteria for Certification of Investigators
Section 5.0 Motor Vehicle Inspection Fee and Frequency
-------
1.0 GENERAL PROVISIONS
This document specifies the tasks, responsibilities, qualifica-
tions, application and renewal procedures which inspectors and
investigators must follow in obtaining state certification.
The above mentioned certification will be necessary for state
investigators and inspectors involved with the Colorado Motor
Vehicle Emissions Inspection of light-duty motor vehicles.
The inspector being any person certified by the A.P.C.C. and
employed by an approved inspection station who inspects motor
vehicles on a pass/fail basis for emissions levels, proper
connection and operation of emission components for vehicle
emissions compliance. This document states the responsibility
of the state investigator will be to inspect motor vehicle
inspection stations and inspectors for proper inspection equip-
ment, correct inspection procedures, proper certification, and
conduct all other supervisory duties delegated to each investigator
under task description and responsibilities in Section four.
1.1 Purpose
The purpose of this report is to delineate criteria for the
certification of inspectors and state investigators in the state's
motor vehicle emissions inspection program. This report sets
forth the task descriptions, responsibilities and provides
guidelines outlining the requirements and qualifications that
must be met and procedures to be followed in applying for
-------
263
certification by inspectors and state investigators. A
sequence of procedures is outlined for inspectors and state
investigators that do not qualify upon application and/or
renewal for certification.
1.2 Accrediting Agency
The Air Pollution Control Commission of the Colorado Department
of Health, Denver, Colorado, is the accrediting agency for
certification of inspectors and state investigators. Assisting
the commission in certifying the above named applicants will
be Colorado State University Industrial Sciences Department
and/or an agency acceptable to the commission.
1.3 Definitions
Unless otherwise specified in the context, the definitions of
this report are:
1.3.1 Motor Vehicle: every self-propelled vehicle
intended primarily for use and operation on the
public highway.
1.3.2 Light Duty Vehicle: any motor vehicle either designed
primarily for transportation of property and rated
at 6001 pounds GVW or less or designed primarily
for transporting persons and having capacity of 12
persons or less. The engine displacement must be
-------
264
exceed aforementioned limitations.
1.3.3 -Inspector: any individual who has met all criteria
required by the Air Pollution Control Commission and
is employed by an approved inspection station to
inspect motor vehicles for vehicle emissions compliance.
1.3.4 Investigator: an individual appointed by the Colorado
State Department of Revenue, who has met all the
criteria required by the Air Pollution Control
Commission, responsible for inspecting approved
Motor Vehicle Inspection Stations and inspectors for
correct inspection equipment, procedure and proper
certification.
1.3.5 Customer: the owner or family member, employee, or
any other person whose use of the vehicle is authorized
by the owner or agent of owner.
1.3.6 Commission: Air Pollution Control Commission.
1.3.7 APCC: Air Pollution Control Commission
1.3.8 Denver Air Quality Control Region: the area enclosed
within the boundaries of the following counties:
Denver, Jefferson, Arapahoe, Adams, Boulder, Douglas,
-------
2.0 INTRODUCTION
The proposed criteria, qualifications, and procedures in this report
were established to provide uniformity in the certification of inspectors
and state investigators involved in the Colorado Motor Emissions
Inspection Program. The implementation of this program is expected
to achieve a reduction in carbon monoxide, hydrocarbon and oxides
of nitrogen emissions from light-duty vehicles operating in
the Denver Air Quality Control Region. Execution of the program
is to be through a network of private, state owned or franchised
inspection stations licensed and regulated by the State of
Colorado (Departments of Health and Revenue). The commission
recognizes the fact that applicants for the positions of inspectors
and state investigators must demonstrate a high level of competence
in the performance of their duties if the Colorado Motor Emissions
Inspection Program is to maintain its effectiveness and integrity.
In the appendix of this document are examples of the tests and
evaluation instruments to be used in determining the competence
and qualifications of inspectors and state investigators for
certification (see appendix C and E). Outlines of the required
courses for inspectors and state investigators training are included
in appendixes A and D respectively. These outlines are intended
specifically for those inspectors and state investigators applying
for initial certification. Any applicant for an inspector's
certificate who fails to pass the competency or certificate renewal
examination will be required to satisfactorily complete a refresher
-------
266
course as stated in appendix B. Each state investigator will be
required to attend a refresher course yearly (see appendix F) before
an appointment to that position is approved.
In addition to attending refresher courses as required, each
inspector will be required to successfully pass an updated examination
related to emission control devices and modifications on new vehicle
models.
Included in this document are three manuals related to automotive
emissions and air pollution control systems, prepared by Delco-Remy
Corporation (see appendix H). These manuals may be used by the inspectors/
investigators while performing their duties. In addition to these
manuals there are many other supplementary materials available.
The bibliography (see appendix I) includes a list of books and manuals
containing pertinent information and specifications relating to vehicle
emission controls. These reference books will provide each applicant
with helpful, self-study material, update and refresher information,
before taking a test when applying for a certificate.
2.1 SAFETY CLAUSE
The commission hereby finds, determines, and declares that the
following criteria and procedures are necessary for the immediate
-------
267
The instructional program cost for the state investigator and
inspector training can be estimated by making the following assumptions:
(1) Rent, insurance, and utilities for training
facility — $600.00 per month
(2) Equipment: infrared analyzer, scope, hand and
miscellaneous tools — $5,400.00
(3) Teaching supplies:
a. handouts and training books — $5.00 per student
b. instructional packet — $240.00
(4) Instructor: $15.00 per hour
Clerical: $ 4.00 per hour
Based on these assumptions, Table I shows an estimated instructional
cost of $1,230.00 for a forty (40)-hour state investigator and
$480.00 for a twelve (12)-hour inspector training program.
The investigator's training would require ten (10) four-hour
sessions, whereas the inspector would attend four (4) three-hour
sessions.
Table II compares the estimated cost of an inspector training
student and the number of students in a class. An identical cost
per student comparison for the investigator training is found in
-------
268
TABLE I
ESTIMATED INSTRUCTION COST FOR
INVESTIGATOR AND INSPECTOR TRAINING.
Expenditure
Investigator
10 Session
40-Hr. Training
Inspector
4 Session
12-Hr. Training
Rent, Insurance,
Utilities
Equipment
Teaching Supplies
Instructor
Clerical
$ 200
$ 150
$ 120
$ 600
$ 160
$ 80
$ 60
$110
$180
$ 50
TOTAL
$1230
$480
-------
269
TABLE II
ESTIMATED INSTRUCTION COST ($) PER STUDENT FOR
INSPECTOR TRAINING*
-------
270
TABLE III
ESTIMATED INSTRUCTION COST ($) PER STUDENT FOR
INVESTIGATOR TRAINING*
-------
3.0 CRITERIA FOR CERTIFICATION OF INSPECTORS
As stated in Senate Bill 393, Section 66-13-28, only inspectors
having the qualifications and passing evaluation tests deemed appropriate
by the commission shall perform emissions inspections. The contents
of this section describe the training criteria and procedures
to be used for certification of inspectors in the Colorado Motor
Vehicle Emissions Inspection Program. The success of any emission
inspection program depends upon adequately trained inspectors.
Table IV shows the training required by applicants with various
backgrounds. This training must be completed by each applicant
before initial certification is granted. As shown in Table V , the
training time required in specified areas will be dependent upon
past experience. It cannot be assumed that just because a person
has mechanical experience he knows emission control systems or
inspection procedures. Considering only the cost of the instructor
in the training class and based on twelve (12) hours of instruction
for every inspector, Table VI reflects the cost per student compared
to various class sizes. It can be seen that as class size increases,
the cost per student decreases. The twelve (12) hours of inspector
training must not be conjectured to be the conclusive number of
training hours for all students; it is, however, the average training
time of all applicant types compared in Table V. Adjustment of
training time will have to be made according to the ability, need,
and experience of each class.
-------
TABLE IV
REQUIRED TRAINING AREAS ON ENGINES AND EMISSIONS
SYSTEMS FOR INSPECTOR CERTIFICATION
Type of Applicant
Tune-Up Mechanic
X
X
X
X
X
X
X
X
X
X
X
X
General Mechanic
X
X
X
X
X
X
X
X
X
X
X
X
Service Station
Mechanic
X
X
X
X
X
X
X
X
X
X
X
X
Automotive Instructor
X
X
X
X
X
X
X
X
X
X
X
X
Existing state safety
Inspector
X
X
X
X
X
X
X
X
X
X
X
X
Lay person
X
X
X
X
X
X
X
X
X
X
X
X
Automotive student
X
X
X
'x
X
X
X
X
X
X
X
-------
TABLE V
TRAINING HOURS REQUIRED IN EMISSIONS SYSTEMS
FOR INSPECTOR CERTIFICATION
Type of Applicant
Tune-Up Mechanic
1.0
1.5
o
•
i—1
.5
1.5
.5
.5
.5
.5
1.0
2.0
1.0
General Mechanic
1.0
1.5
1.0
.5
1.5
.5
.5
.5
.5
1.0
2.0
1.5
Service Station
Mechanic
1.0
1.5
1.0
.5
1.0
.5
.5
.5
.5
1.5
2.5
1.5
Automotive instructor
1.0
1.5
1.0
.5
1.0
.25
.25
.5
.5
.5
2.0
1.0
Existing state safety
Inspector
1.0
1.0
.5
.5
.5
.5
1.0
1.0
.5
1.0
3.0
1.5
Lay person
1.0
1.5
1.0
.5
1.5
1.0
1.0
1.0
1.0
1.0
3.0
1.5
Automotive student
1.0
1.0
1.0
.5
1.5
.5
1.0
1.0
1.0
1.0
3.0
-------
TABLE VI
INSTRUCTOR COST OF INSPECTOR TRAINING*/STUDENT VS. CLASS SIZE
0 6 8 10 12 15 18 20
NUMBER OF STUDENTS IN CLASS
-------
275
This section further delineates the inspector's responsibilities,
experience and education requirements, examinations, place of
application, certificate term, certificate renewal procedures and
reasons for revocation of certificate. The requirements that are
to be fulfilled by each inspector applicant for certification are
as follows.
3.1 INSPECTOR CERTIFICATION
3.1.1 Tasks and Duties Necessary to Conduct Ongoing Program:
3.1.1.1 Inspection: The inspector will conduct a
motor vehicle emissions inspection on all
light-duty vehicles, except those vehicles
exempted in the state emissions handbook, as
required by the commission in accordance
with the Colorado Idle Emissions Test Procedure.
The inspection will consist of a hydrocarbon
and carbon monoxide measurement at the exhaust
pipe at idle and 2500 revolutions per minute.
He will also check under the hood and at other
appropriate locations for proper connection
and operation of all emissions control hardware
as installed by manufacturer. He will also
check for any retrofit devices and their
proper operation as required by the
-------
276
3.1.1.2 Equipment Surveillance;
(a) HC-CO Analyzer - The inspector will be
required to understand the principles of
operation of the analyzer. The inspector
must be able to evaluate analyzer performance
via use of span gas or electronic span,
check analyzer and sample hose for vacuum leak(s)
and perform normal maintenance on analyzer.
(b) Tachometer - The inspector must have
knowledge in normal maintenance, use and care
of the meter. He must also possess skill
in checking and setting calibration.
3.1.1.3 Reports: Any individual performing emissions
inspection will know the flow of reports for
passed and failed vehicles. The inspector
will also know the various required reports
and information that he must furnish to the
commission.
3.1.1.4 Records: The inspector will retain and
keep in an organized manner all records
pertaining to vehicle inspection. Records
will be available for review by investigators,
members of commission, Air Pollution Board
or other duly authorized individuals at any
-------
277
3.2 APPLICATION FOR INSPECTOR CERTIFICATION
3.2.1 Competency, Experience; No person will be certified as
an inspector unless he has successfully completed the
required training, demonstrated his competence, ability,
and shown proof of experience to Colorado State Univer-
sity (training agency) by such tests, examinations
or other standards prescribed.
3.2.1.1 Proof of Experience: Applicants for an inspector's
certificate must furnish to Colorado State University
(training agency) personal references, or certificate (s)
showing evidence that the applicant possess the
necessary experience in emissions systems.
(a) In lieu of Experience - At its option, the
training agency may accept in lieu of experience,
evidence that the applicant attended and satis-
factorily completed a course of instruction in
motor vehicle emission control systems conducted
by one or more of the following:
1) Public high school, vocational school or
Junior College*
2) Industrial or trade school*
3) Vehicle manufacturer
-------
278
3.2.2 Inspector Examination: Applicants for an inspector
certificate must successfully complete a test or examina-
tion prescribed by Colorado State University (training
agency) with a grade score of not less than 80 percent.
3.2.2.1 Examination Content; The examination(s) will
consist of questions encompassing mathematical
problems showing level of competancy (5th grade),
pre-inspection procedures, inspection procedures,
instrument care and use, knowledge of devices
and systems of emissions control.
The questions will be of the true-false, multiple-
choice and short answer type. A sample of the
test may be found in appendix C.
(a) If the training agency deems it necessary,
the applicant will also be required to identify
displayed emissions parts and hardware and perform
a check for proper connection and operation of
components on a bench simulated emission system.
Example: Identify all emission hardware displayed
on a bench system that would be found on a 1974
Ford 351W engine, 2 barrel, air conditioning and
automatic transmission. In addition, with an
auxiliary vacuum and battery source check for
proper operation of a solenoid vacuum switch,
-------
279
and idle stop solenoid.
3.2.2.2 Failure of Inspector Examination: Any person
failing the inspector's examination prescribed
by the training agency may reapply for certifica-
tion after satisfactorily completing the following:
(a) A refresher course in motor vehicle emissions
control and retake the written test a second time.
An outline of refresher course will be found in
appendix B.
(b) Any applicant failing the test a second time
may,at his discretion, ask for a practical test
on a bench simulated model or a third retest
after completing a second refresher course in
motor vehicle emissions control.
3.2.3 Education: Applicants must demonstrate ability to read,
write and perform 5th grade level mathematical computations
included in competency test as required by Colorado State
University (training agency).
3.2.4 Where to Apply: Persons wishing to become certified
inspectors may apply to the training agency. Applications
must be completed, signed and postmarked not less than
30 days prior to date of the test. A list of testing
dates for the fiscal year will appear publicly at the
State Employment Office and other places deemed necessary
-------
280
3.3 CERTIFICATION TERM AND FEE
3.3.1 Certification Term: Certification issued to motor vehicle
emissions inspectors shall expire two years from date of
issue unless other action is taken as stated in section
3.5 at which time the certificate becomes void immediately.
3.2.2 Certification Fee: The fee for certification issued to
official motor vehicle emissions inspectors will be
established by legislature and will accompany the appli-
cation sent to Colorado State University, Industrial
Science Department, Fort Collins, Colorado 80523.
Regardless of certification results the appropriate fee
will remain with the training agency.
3.4 RENEWAL OF INSPECTOR'S CERTIFICATION
3.4.1 Examination: Application for certificate renewal must be
made within 90 days prior to the expiration date of current
certificate. Each applicant will be required to success-
fully pass an examination(s) prescribed by the training
agency. Tests for certificate renewal will be given
monthly and applications must be completed, signed and
postmarked not less than 25 days prior to date of the test.
Application forms will be available from Colorado State
University and the commission. If application for renewal
is not completed and received within the 90 days period,
-------
281
initial certification set forth in section 3.2.
3.4.1.1 The examination will consist of multiple choice,
true-false, and short answer questions testing
the updated knowledge of the inspector over new
and/or modified emissions devices on new model
vehicles. In addition, a time limit test containing
questions requiring the use of an emissions
manual covering the identification of new emissions
hardware may be asked. The examination will
be updated July 1 of each year. Modification of
the test will correspond to changes and/or additions
of new model emissions devices (see appendix G).
3.4.2 Where to Apply: Applications for renewal of inspector's
certificate will be accepted by Colorado State University,
Industrial Science Department, Fort Collins, Colorado 80523
that satisfy the time limits as stated in section 3.4.1.
3.4.3 Renewal Fee: The certificate renewal fee for motor vehicle
emissions inspectors will be established by legislature.
The fee must accompany the application for renewal and regardless
of test outcome the appropriate fee will remain with Colorado
State University (training agency).
3.5 DENIAL, SUSPENSION OR REVOCATION OF CERTIFICATE
3.5.1 Proof of Unfitness: The commission may deny, suspend,
revoke or refuse to renew the certificate issued to an
inspector upon determining that the inspector or applicant
-------
282
3.5.1.1 Fictitious Name: The commission may suspend,
revoke, or refuse to renew the certificate if it is
determined that an applicant or holder of certificate
used a false or fictitious name on records, reports
or application pertaining to the emissions inspection
program.
3.5.1.2 False Statements: The commission may suspend,
revoke, or refuse to renew the certificate if the
applicant has knowingly made any false statements
or concealed any material fact in any application
for such certificate.
3.5.1.3 Violated Department Regulations: The commission
may suspend, revoke, or refuse to renew the certifi-
cate if an applicant has violated one or more of
the regulations developed by the commission.
3.5.1.4 Improper Service: The commission may suspend,
revoke, or refuse to renew the license issued to
an inspector when he has failed to properly inspect
a vehicle in compliance with regulations adopted
by the commission.
3.5.2 Fails Examination: The commission may refuse to issue or
renew a certificate to an applicant who fails to satisfactorily
pass an examination.
3.5.3 Evidence of Competence: The commission may refuse to issue
a certificate to an applicant who fails to provide satisfactory
evidence of abilities and competence as specified in section
-------
283
3.5.4 Negligence and/or Incompetency: The commission may deny,
suspend, revoke or refuse to renew the certificate if the
inspector is guilty of gross negligence or repeated gross
incompetent conduct of duties.
3.5.4.1 Incompetency; The commission may deny, suspend,
revoke or refuse to renew the certificate if the
inspector is guilty of willful and repeated incompetent
performance of inspections and/or related customer
services.
3.5.4.2 Negligence: The commission may deny, suspend,
revoke or refuse to renew the certificate if the
inspector is guilty of intentional and repeated
negligence of safety procedures and workmanship
in conducting inspections.
3.5.5 Failure to Comply: The commission may deny, suspend, revoke
or refuse to renew the certificate of an inspector upon
intentional failure to comply with any provisions, rules,
inspection procedures or regulations promulgated by the
commission and training agency.
3.5.6 Aiding and Abetting: The commission may deny, suspend,
revoke or refuse to renew a certificate to an inspector who
intentionally aids and abets a person who willfully modifies
hardware or informs any person of sub-standard inspection
-------
284
3.6 CERTIFICATE VOID
3.6.1 When Not Employed: An inspector's certificate is void when
not employed by a licensed inspection station.
3.6.2 Retention of Inspector's Certificate: An unemployed inspec
may retain his/her inspector's certificate and upon re-
employment in an official emissions inspection station the
certificate again becomes valid for remaining period of two
-------
4.0 CRITERIA FOR CERTIFICATION OF INVESTIGATORS
This section of the document delineates the tasks and duties
required of each state investigator. Described in this section
is the criteria and procedures to be used for certification of
investigators in the Colorado Motor Vehicle Emissions Inspection
Program. The necessity of the state investigator's expertise,
competence, and training cannot be overemphasized. The state
investigator's ability to fulfill his responsibilities will be a
major contribution to a successful and ongoing emissions inspection
program. As shown in Table VII, all applicants must complete training
in all of the thirteen (13) areas regardless of background or
experience. Although training in each area is required, the length
of instruction in hours varies according to the type of applicant.
Table viii exniDits tne varying amounts of training time required
according to the applicant's background. The training course is based
on a forty (40) hour curriculum which corresponds to the average
length of instruction for the applicants listed. Shown in Table IX
is the cost per student compared to the number of students in a
class. This cost is only that of the instructor for each training
class. As can be expected, the cost per student decreases from $100
to $30 per student as class size increases from six (6) to twenty (20),
respectively.
-------
TABLE VII
REQUIRED TRAINING AREAS ON ENGINES AND EMISSIONS SYSTEMS
FOR INVESTIGATOR * CERTIFICATION
Type of Applicant
Tune-Up Mechanic
' v
X
X
X
X
X
X
X
X
X
X
X
X
X
General Mechanic
X
X
X
X
X
X
X
X
X
X
X
X
X
Service Station
Mechanic
X
X
X
X
X
X
X
X
X
X
X
X
X
Automotive Instructor
X
X
X
X
X
X
X
X
X
X
X
X
X
Existing state safety
Inspector
X
X
X
X
X
X
X
X
X
X
V
il
X
X
Automotive Student
X
1
X
X
X
X
X
X
X
X
X
X
X
X
NJ
00
-------
TABLE VIII
TRAINING HOURS REQUIRED ON EMISSION SYSTEMS
FOR INVESTIGATOR* CERTIFICATION
Type of Applicant
Tune-Up Mechanic
3.0
4.0
1.0
2.0
2.0
1.5
2.0
2.5
2.5
3.0
8.0
"" "7*
4.0
2.0
General Mechanic
3.0
4.0
1.0
2.0
2.0
1.5
2.0
2.5
2.5
3.0
8.0
4.0
2.0
Service Station
Mechanic
3.0
4.0
1.0
2.0
2.0
1.5
2.0
2.5
3.0
3.0
8.0
4.0
4.0
Automotive Instructor
3.0
4.0
1.0
2.0
2.0
1.0
1.5
2.0
3.0
3.0
6.0
4.0
2.0
Certified safety
Inspector
2.0
3.0
1.0
1.0
1.5
1.5
2.0
2.5
2.5
3.0
8.0
5.0
4.0
Automotive Student
3.0
5.0
2.0
2.5
3.0
2.0
2.0
3.0
3.0
4.0
8.0
5.0
4.0
-------
TABLE IX
INSTRUCTOR COST OF INVESTIGATOR TRAINING*/STUDENT VS. CLASS SIZE
0 6 8 10 12 15 18 20
NUMBER OF STUDENTS IN CLASS
-------
289
Delineated in this portion of the report are the state investigator's
responsibilities, competency, experience and education requirements,
examinations, place of application, appointment procedure and
term, methods of renewal and requisites for certificate tetention.
The following criteria will assist in fulfilling the requirements
established by section 66-31-28 of Senate Bill 393, stating
state-employed investigators shall pass qualification tests as
developed and approved by the commission.
4.1 INVESTIGATOR CERTIFICATION
4.1.1 Task and Duties Necessary to Conduct Ongoing Program:
Each state-employed investigator will be required to
complete the specified investigator's emission control
training course (see appendix D) and to perform
the following:
4.1.1.1 Equipment Surveillance: In order that a satis-
factory degree of quality control can be
maintained in the inspection program the
state investigator will be required to understand
the operating principles and use of inspection
equipment.
(a) HC-CO Analyzer - The investigator will be
-------
290
operation of the analyzer. The investigator
must be able to evaluate analyzer performance
via use of span gas or electronic span, check
analyzer and sample hose for vacuum leak(s)
and check if proper care and maintenance has
been performed on analyzer by the inspector,
(b) Tachometer - The investigator must know
normal maintenance use and care of meter and
possess skill in checking and setting calibration.
4.1.1.2 Inspection Procedures: The investigator will
be required to demonstrate correct inspection
procedures and observe inspector for proper
performance of inspection.
4.1.1.3 Enforcement: The investigator will be responsible
to enforce all state emissions inspection
policies as stated in Colorado Motor Vehicle
Emissions Handbook. In the event an inspector
or station violates any inspection policy, the
state investigator with authority from the Executive
Director of Revenue will have the prerogative to
remove the certificate(s), impound stickers and
terminate any further inspections.
4.1.1.4 Inspection of Stations: Investigator will
inspect fleet and private inspection stations
for proper equipment, stock of parts and area
of inspection for compliance with regulations.
-------
291
order, form and proper storage.
4.1.1.5 Complaints: The investigator will investigate
and act as a mediator where complaints arise
between customer and inspector or inspection
station. If situation can not be resolved by
investigator, it will be brought before the
the Board for satisfaction of all concerned,
(a) Complaint flow chart:
Customer Investigator Board for motor
vehicle safety inspections
4.1.1.6 Discipline: The investigator will be required
to take appropriate action on disciplinary
problems of inspectors as stated in Colorado
Motor Vehicle Emissions Handbook. A case
involving suing action between customer, station,
inspector or investigator will be entered
and settled in a court of law.
4.1.1.7 Mechanical Skills: The investigator will be
required to perform normal mechanical skills
as related to the emissions test procedure.
4.2 APPLICATION FOR INVESTIGATOR CERTIFICATION
4.2.1 Competency: Proof of competency will be shown by
passing the National Institute for Automotive Service
Excellence Test, covering tune-up and fuel, or equivalent
-------
292
by Colorado State University (training agency) with a
grade score of not less than 80 percent.
4.2.2 Investigator Examination: Applicants for an investigator
certificate must successfully complete a motor vehicle
emissions test or examination prescribed by the training
agency with a grade score of not less than 80 percent.
4.2.2.1 Examination Content: The examination(s) will con-
sist of questions covering pre-inspection procedures,
inspection procedures, instrument care and use,
knowledge of devices and emissions systems;
all of which are imperative to the program in
maintaining quality control. It will also consist
of an emission related situation requiring an
essay response of one page or less demonstrating
competency in written communication. The
questions will be true-false, multiple-choice,
short answer, and essay (see appendix E).
Every investigator must be thoroughly familiar
with emissions systems and parts to maintain
integrity of the inspection program, therefore,
the applicant will also be required to identify
displayed emissions parts and hardware and check
for proper operation of emission components on
a bench simulated system using a test light,
voltmeter and ohnnneter in conjunction with an
-------
293
4.2.3 Education: The investigator must have a high school
education or G.E.D. and demonstrate verbal and written
competencies for effective communication.
4.2.3.1 Demonstration of Competencies: Each applicant
will demonstrate his written competency by success-
fully completing the test; verbal competency will
be demonstrated by a personal interview.
4.2.4 Where to Apply: Application for investigator certification
will be submitted to the Department of Revenue, Motor
Vehicle Department, 1140 West 6th Avenue, Denver, Colorado
80204.
4.3 CERTIFICATION PROCEDURE AND TERM
4.3.1 Process in Attaining Certification:
a) application
b) meet Civil Service regulations
c) provisional appointment
d) meet additional job requirements and proficiency
e) certification
4.3.2 Appointment: Upon meeting Civil Service requirements the
applicant will be appointed by the Department of Revenue on
a provisional basis until additional job requirements
identified in Sections 4.2.1 and 4.2.2 are met, except as
amended in Section 4.3.3.
4.3.3 Failure to Meet Requirements for Certification: Within
ninety (90) days of provisional appointment the investigator
-------
294
and 4.2.2. If these requirements are not met, certification
will be denied.
4.3.4 Test Application: Investigators' application for the test
will be submitted to Colorado State University, Department of
Industrial Sciences, Fort Collins, Colorado 80523 (training
agency) and must be completed and postmarked not less than
two weeks (14 days) prior to test date.
4.4 CERTIFICATION FEE AND RETENTION
4.4.1 Fee: The fee for an investigator's certificate will be
only those costs incurred by taking the appropriate tests
and to cover administrative expenses.
4.4.2 Retention of Investigator's Certificate: Retention of
investigator's certificate will be subject to fulfilling
updated requirements established by the Department of
Revenue and the Commission (see appendixes F and G).
4.4.2.1 Retention Requirements: Each investigator upon
application for retention of certificate shall be
required to attend 16 hours of update training before
June 1 of each year, as deemed necessary by the
Commission, relating to modification and changes
of emission control hardware.
4.4.2.2 Proof of Maintenance of Knowledge: The investigator
will demonstrate his knowledge by passing a test
with a score of not less than 80 percent. The
-------
295
changes, modifications and additions of emission
control devices by vehicle manufacturers dictate.
4.5 CERTIFICATE VOID
4.5.1 When Not Employed; An investigator's certificate will be
void when not employed by the Colorado Department of Revenue.
4.5.1.1 While on Leave: During leave of absence, sick leave,
vacation, or any other form of time off, the
investigator's certificate will be void and no
investigation may be performed. Upon return from
investigator's absence, his certificate will be
-------
APPENDIX A
-------
297
(Sample Outline)
INSPECTOR'S COURSE OUTLINE FOR
EMISSIONS INSPECTION PROGRAM
I. POLLUTANTS AND EXHAUST ANALYZERS
A. Air Pollution
1. HC, CO, NOx: Defined and explained
B. HC/CO Analyzers and Use
1. Operation
2. Gas and Electronic Span
3. Maintenance
4. Pre-test preparation
a. Engine temperature
b. Calibration
c. Connections
d. Conducting test
e. Additional uses
II. TEST LANE PROCEDURE
A. Safety
1. Fire
-------
298
(Sample Outline)
B. Testing the Vehicle
C. Customer Relations
1. Failed Vehicles
D. Inspection Forms
1. Fees
2. Completing of forms and filing
3. Security
III. ENGINE AND IGNITION THEORY
A. Engine Requirements
B. Ignition Theory and Components
1. Standard Ignition Systems
2. Solid State Ignition Systems
3. Ignition Effects on Emissions
IV CARBURETION
A. Principles of Pressure
B. Vacuum Principles
1. Ported
2. Manifold
3. Venturi
-------
299
(Sample Outline)
D. Idle Mixture Limiters
E. Throttle Positioners and Idle Stop Solenoids
1. Checking and testing
V. THEORY OF EMISSION CONTROLS (GENERAL)
A. Systems and Similarity Between Manufacturers
1. Positive Crankcase ventilation
2. Heated Intake Air System
3. Air Injection System
4. Fuel Evaporative Systems
5. Ignition Spark Controls
6. Exhaust Gas Recirculation
B. Use of Exhaust Emission Manuals
VI. Specific Emission Controls
A. Positive Crankcase Ventilation
1. Types of PCV Systems
2. Testing and Checking of Components
B. Heated Intake Air Systems
1. Types
2. Control devices
-------
300
(Sample Outline)
Air Injection Systems
1. System Components
2. Hoses and Plumbing
3. Vacuum Signals
4. Testing and Checking of Components
Fuel Evaporative Systems
1. Fuel Tank Caps
2. Vapor Storage
3. Fuel and vacuum lines (connection)
4. Purging controls
5. Carburetor venting
6. Testing and checking components
Ignition Spark Controls
1. Ignition Timing Controls
a. Solenoids
b. Time relays
c. Vacuum delay valves
d. Transmission switches
e. Temperature override and thermal switches
f. Deceleration vacuum control valves
g. Speed sensors and amplifier modules
-------
301
(Sample Outline)
F. Exhaust Gas Recirculation Systems
1. EGR Controls
a. Floor jets
b. EGR valves
c. Vacuum hose routing
d. Temperature override switches
e. Deceleration vacuum control valves
f. Speed sensors and amplifier modules
g. Testing of systems and components
VII. NEW MODEL -EMISSION SYSTEMS AND MODIFICATIONS
-------
APPENDIX B
REFRESHER COURSE REQUIREMENT AND CONTENT FOR
-------
(SAMPLE ONLY)
REFRESHER COURSE REQUIREMENT AND CONTENT
FOR APPLICANT CERTIFICATION AND
INSPECTOR CERTIFICATE RENEWAL
Any applicant/inspector who fails to pass the competency or
certificate renewal examination with the required 80% score
will be required to take a refresher course in emissions
systems. As indicated by the test questions missed it can
be determined what area(s) the applicant lacks knowledge.
If the applicant so desires he may take the entire inspector's
emission course as outlined but will only be required to
enroll in the section(s) of the course he needs additional
training. For example, the applicant shows a deficiency in
Exhaust Gas Recirculation; therefore the only section of
the course requiring attendence by the applicant would be
the EGR unit.
-------
APPENDIX C
-------
304a
INSPECTOR EXAMINATION
The following inspectors' examination is an example only of the
Type of test that will be used to certify an inspector to conduct
a tail pipe and under hood vehicle emissions inspection. The
examination consists of questions showing level of compentency
in mathematical problem solving (5th grade), inspection procedures,
instrument use, knowledge of devices and systems of emissions
control.
The inspector's application procedures incompassing the examination
-------
(Sample Only)
INSPECTOR COMPETENCY EXAMINATION
Multiple-Choice: Place the letter corresponding to the best
answer in the space provided.
1. HC is the symbol for
a. nitrogen
b. sulfur
c. oxygen
d. hydrocarbons
2. CO is the symbol for
a. hydrocarbons
b. carbon monoxide
c. chlorine
d. calcium
3. An engine is equipped with a throttle stop solenoid
(anti-dieseling solenoid). At what time(s) should
the plunger be in the extended position (solenoid
energized)?
a. only above 30 M.P.H.
b. only below 30 M.P.H.
c. any time ignition switch is "on"
d. none of the above
4. On an engine with an air injection system with a
diverter valve air should be "dumped" momentarily
to the atmosphere when
a. the engine is decelerating
b. the engine is accelerating
c. the engine speed is below 2,000 R.P.M.
5. When checking for a fuel vapor leak with the HC-CO
analyzer probe and a leak is present you would
most likely see what meter reading?
a. High HC and CO
b. only high CO
c. only high HC
d. would not be detected
-------
306
True-False: Circle T If statement is true, F if the state-
ment is false.
T F 1. A vehicle is equipped with a heated air intake
system with a vacuum motor controlled air door;
regardless of underhood temperature, when the
engine is off, the air door will be in the cold
air mode (position).
T F 2. On a GM vehicle with a CEC solenoid the idle speed
is controlled and set by the solenoid plunger.
T F 3. It is not necessary to allow the engine to reach
normal operating temperature to perform an HC-CO
emissions test with an infra-red analyzer.
T F 4. Some vehicles with spark control systems allow
vacuum advance to the distributor regardless of
gear selection when the engine coolant is below
a specified temperature.
T F 5. You inspect a 1972 vehicle with the air cleaner
lid turned upside down. This is O.K. because
this does not affect any of the emission systems.
Short Answer: Fill in the blank with the correct missing word
or phrase.
1. The vacuum motor on a heated air induction system must
be operated by vacuum.
(source)
2. The infrared analyzer test probe must be inserted into the
tail pipe at least inches to obtain an
-------
307
3. Explain briefly how a simple test (without gauges) can
be performed to check if an air injection pump
has any air output.
4. What, if any, are the visible differences between
a distributor with a retard solenoid and one with
an advance solenoid on a Chrysler Corporation
engine?
5. A Ford Motor Company engine is equipped with a
dual diaphragm vacuum advance mechanism. Which
diaphragm should be connected to manifold vacuum?
Math Problems: Solve the following
1. Add 43 + 21 + 19 = 21.3 + 15.9 = 13.02 + 67.5 =
2. Subtract 43 - 29 = 89.1 - 74.8 =
-------
308
3. Multiply 107 X 39 = 51.3 X 6.2 =
442 X 65% =
4. Divide 192 t 4 = 56.23 4 21 =
Practical Test:
Upon completion of this written examination you will be required
to perform an actual emissions test on a vehicle according to
the State of Colorado's Inspection Handbook in the presence
-------
APPENDIX D
-------
310
(Sample Outline)
INVESTIGATOR COURSE OUTLINE FOR
EMISSION CONTROL AND INSPECTION PROGRAM
I. POLLUTANTS AND EXHAUST ANALYZERS
A. Air Pollution
1. HC, CO, NOx: Defined and explained
a. Formation of HC, CO, NOx in engine
2. Effects on human, plant, and animal life
B. Exhaust Analyzers
1. Principles of Operation
a. Electronic and span gas
2. Pre-testing Preparations
a. Engine temperature
b. Calibration and span
c. Proper "hook-up"
d. Additional uses
3. Maintenance of analyzer
a. Filters
b. Water traps
c. Checking air flow rate
d. Hose and fitting leaks
4. Test lane procedure
a. Safety
b. Customer relations
1) Failed vehicles
c. Forms
-------
311
(Sample Outline)
II. ENGINE AND IGNITION THEORY
A. Engine Requirements
1. Fuel - air - ignition
a. Heat and power
B. Ignition Theory
1. Purpose
2. Components
a. Standard ignition
b. Solid state types
c. Diagnosis
3. Ignition effects on emissions
a. HC, CO, N0X
b. Advance controls
1) Testing and checking of components
III. CARBURETION
A. Carburetion Principles
1. Pressure and effects
2. Air cleaners
3. Carburetor vacuum principles
a. Manifold
b. Ported
c. Venturi
4. Venting
-------
6.
7.
312
(Sample Outline)
Chokes
Exhaust restrictors and heat valves
B. Throttle Positioners
1. Idle stop solenoids
THEORY OF EMISSION CONTROLS (GENERAL)
A. Relation of Controls to Emission Reduction
1. Positive crankcase ventilation
2. Heated intake air system
3. Air injection system
4. Fuel evaporative system
5. Ignition spark controls
6. Exhaust gas recirculation
SPECIFIC EMISSION CONTROLS
A. Positive Crankcase Ventilation
1. Operation and purpose
2. Types of PCU systems
3. Testing and checking system
B. Heated Intake Air Systems
1. Types
a. Thermostatic
b. Vacuum motor
1) Controls and operation
-------
313
(Sample Outline)
Air Injection Systems
1. Components and checks
a. Pump
b. Relief valves
c. Diverter and check valves
d. Hoses and vacuum signals
e. Testing of components
Fuel Evaporative Systems
1. Fuel tanks
a. Caps and vents
2. Vapor storage
a. Crankcase
b. Canisters
1) Purging methods
3. Carburetor venting
4. Methods of checking and testing components
Ignition Spark Controls
1. Ignition timing controls
a. Solenoids
b. Time relays
c. Vacuum delay valves
d. Transmission switches
e. Temperature override and thermal switches
f. Deceleration vacuum advance control valves
g. Speed sensors
1) Amplifier modules
-------
314
(Sample Outline)
F. Exhaust Gas Recirculation
1. Principle of operation
a. Purpose
b. Combustion temperatures
2. EGR Controls
a. Exhaust recycle requirements vs. engine operating
modes
b. Flood jets
c. EGR valves
d. Vacuum operated EGR
1) Override switches
2) Ported vacuum signals
3) Venturi vacuum signals
a) vacuum amplifier
4) Hoses and routing
5) Testing and checking
VI. INSPECTION POLICIES
A. Inspector Surveillance
B. Fee Collection and Security
C. Complaints and procedures
VII. NEW MODEL EMISSION SYSTEMS AND MODIFICATIONS
-------
APPENDIX E
-------
(SAMPLE ONLY)
INVESTIGATOR COMPETENCY EXAMINATION
Multiple-Choice: Place the letter corresponding to the
best answer in the space provided.
1. Evaporation Emission control systems on 1970-71
American Motors, Chrysler and some Ford cars
a. store fuel vapors in the engine crankcase,
drawing them through the PCV system when
wngine is started and running
b. store fuel vapors in twin charcoal canisters
c. store fuel vapors in the intake manifold when
engine is not running
2. Since 1968, all U.S.—built passenger cars and
light trucks have been equipped with
a. a recirculating PCV system
b. an open PCV system
c. a closed PCV system
3. The Exhaust Gas Recirculation system is designed
primarily to
a. reduce hydrocarbon emissions
b. reduce carbon monoxide emissions
c. reduce nitrogen oxide emissions
4. On an engine with an air injection system with a
diverter valve air should be "dumped" momentarily
to the atmosphere when
a. the engine is decelerating
b. the engine is accelerating
c. the engine speed is below 2,000 R.P.M.
5. A distributor advance mechanism that provides
improper timing may cause
a. poor M.P.G.
b. possible high speed miss
c. ineffective emission control
d. all of the above
-------
317
6. Which instrument can be used to test for high
HC when an engine tuneup has been performed
using manufacturers specifications?
a. timing light
b. tach dwell
c. vacuum gauge.
d. all of the above
e. none of the above
True-False: Circle T if statement is true, F if the state-
ment is false.
Exhaust emissions are greatest during periods
of deceleration and idle.
A mechanic cannot disconnect pollution control
devices but it is O.K. (legal) for a person
to do it on his own car.
An automatic transmission switch used on a TCS
system that is identified in the diagram as normally
open should not have continuity if checked when
engine is running and selector is in neutral.
Extremely high HC and CO readings are indications
of a flooding carburetor when testing from idle
to 1,000 R.P.M.
When both HC and CO are high during idle R.P.M.
the key to an overrich diagnosis is an excessively
high CO reading.
T F 1.
T F 2.
T F 3.
T F 4.
T F 5.
Short Answer: Fill in the blank with the correct missing
work or phrase.
1. A type 4 (closed) crankcase ventilation system
has a (vented/non-vented)
oil filler cap.
2.
On a vehicle with a V-8 engine and air injection
there are check valves in the
-------
318
3. Explain briefly but thoroughly how a vehicle with
a transmission controlled spark system could be
checked for allowing proper spark advance in
3rd gear in the shop. Car has automatic transmission.
EssayvQuestion: As an investigator you are faced with the
following situation. Write out a solution
to this situation in one page or less as
how you would try and resolve the problem.
Problem: A customer had an emissions inspection
performed on his vehicle which has a drain
hole in the muffler. The inspector would
not pass the vehicle because he contends
the hole is of sufficient size to dilute
the sample. The customer claims it is of
little significance. What would you suggest?
Practical Test: You will be required to watch an emissions
inspection on a live vehicle and note any
malpractices that may be performed by the
-------
APPENDIX F
-------
(SAMPLE ONLY)
REFRESHER COURSE REQUIREMENT AND CONTENT
FOR INVESTIGATOR REAPPOINTMENT
As stated in Section 4.4.2.1 of this document each investigator,
in order to retain certification will be required to attend
update training before June 1 of each year, as deemed necessary
by the commission, relating to modification and changes of
emission control devices. Unit VII of the regular inspectors
training course encompasses new model and modified emission
systems by vehicle manufacturers. Enrollment in this unit
will be required of each investigator , annually, or as deemed
necessary by the commission, for retention of certification.
-------
APPENDIX G
INVESTIGATOR'S AND INSPECTOR'S
-------
(SAMPLE ONLY)
INVESTIGATOR'S AND INSPECTOR'S UPDATE EXANINATION
The following example is part of a typical examination that will
be given each investigator and inspector when application for
certification renewal is made. The applicants will be allowed an
emissions manual to answer problem H1. There will be a time limit
to complete the examination. Because of the numerous changes and
modifications in vehicle emission controls from year to year, the
need for an update test is imperative.
PROBLEM #1: List all the emission controls that are used on
the following engines and in their respective
model year. Where modifications or new additions
occur, identify component and/or system location
(all must be correct).
1974-1975 Chevrolet Impala with: 350 engine,
2 barrel carburetor, air conditioner, automatic
transmission.
PROBLEM // 2: Identify six (6) displayed vehicle emission control
devices that are found on 1975 automobiles (all must
be correct).
QUESTIONS: T F
On some 1975 Chrysler products a carburetor solenoid
is used to prevent the catalyst from overheating.
-------
323
The EGR modulator on 1975 General Motors products
regulates vacuum to the EGR valve according to:
(circle correct response letter)
a) road speed
b) transmission gear
c) exhaust back-pressure
PRACTICAL TEST:
Conduct an inspection of a current model year vehicle
under the supervision of a member from the training
-------
APPENDIX H
-------
TABLE OF CONTENTS
Page No.
Page No.
Page No.
Automotive Emissions
Exhaust Emission Systems .
. .330
Ford Combustion System
.3 35
in relation to Air Pollution .
. 326
Vacuum Spark Advance .
. .331
Service Requirements . .'.
. 336
Introduction
. 325
Typical Vacuum Control
Engine Tune-Up Procedure ,
,.338
Crankcase Emission Systems
. 327
Circuit
. .331
Batteries and Cables
.339
Open PCV Systems
. 326
Dual Action Vacuum
Cranking Motor and
Closed PCV Systems
. 328
Advance-Retard Control .
. .331
Circuit
. 340
PCV Valve Operation ...
. 328
Thermostatic Vacuum
Engine Mechanical
Dual Action Valve
. 329
Switch
. .332
Condition
. . 340
Practical Check of PCV
Vacuum Advance Valve .
. .332
Spark Plugs
. .341
Systems
. 330
Idle Stop Solenoid
. .332
Distributor and Ignition
Testing PCV Systems
. 330
Thermostatically Controlled
Circuit Checks
. . 341
Servicing PCV System .. .
. 330
Air Cleaner
. .333
INTRODUCTION
The purpose of The Power Service Manuals (Vol.
No. ! and Vol. No. 2) is to help you become famil-
iar with the crankcase and exhaust emission control
systems now required on all cars, according to Fed-
eral law. The No. 1 Manual contains an explanation
of the PCV or Positive Crankcase Ventilation sys-
tem, and the General Motors CCS or Controlled
Combustion System. At a later date, a No. 2 Power
Service Manual will be available. It will contain an
explanation of the General Motors AIR or Air In-
jector Reactor system and the Chrysler CAP system.
The required service on emission systems is quite
limited The major control of emissions is accom-
plished by performing periodic engine tune-ups that
maintain optimum engine performance at all times.
For that reason, this No. 1 Manual contains a brief
description of the procedures performed during the
first half of a complete engine tune-up. The remain-
ing half of the engine tune-up procedures will be
covered in the No. 2 Manual.
Crankcase emission control systems function in
mucli the same manner on all makes of cars. This
Manual will describe a typical system. When you
understand the basic system, you should have no
trouble in identifying the components and servicing
the system on any car.
The various exhaust emission control systems have
certain common characteristics, too. Generally
speaking, all engines equipped with an exhaust emis-
sion control system have these modifications. ..
1. Specifically calibrated carburetor
2. Sperfically calibrated distributor
3. Retarded timing
4. Higher idle speed
5. Higher operating temperatures
In addition, they will incorporate control units of
the type used in either the CCS or AIR systems.
Again with a basic understanding of system com-
ponents, you should have no trouble in servicing
similar systems on any car.
Along with this First Manual, you received an
examination that will test your understanding of the
material in the booklet. To complete the exam,
select the correct answer from the three suggestions.
Indicate your choice, and mark down the page
number where you located the answer.
You're on your own, so you can proceed as you
choose. You can read the examination questions,
and then watch for the answers as you review the
text and study the illustrations. Or you can study
the explanations and the drawings, and then under-
take to answer the questions. You will receive a
diploma after you successfully complete this exami-
nation, and the one that will come to you with the
Second Manual.
-------
AUTOMOTIVE EMISSIONS
IN RELATION TO AIR POLLUTION
The automobile is just one of many contributors to
air pollution. However, it's the one that interests us
... because it's a part of our job to help individual
car owners and automotive service personnei live up
to the rules and regulations that now govern auto-
motive emissions.
The automobile contributes to air pollution simply
because it uses gasoline, a fuel made up of hydro-
carbons. When unburned hydrocarbons escape into
the air, they contribute to its contamination ... and
that's the definition of air pollution.
The automobile has four sources (Fig. 1) for the
release of unburned hydrocarbons into the atmo-
sphere. The first is the crankcase, where blowby
gases account for about 20% of the total. The
second source is the exhaust, responsible for approx-
imately 60% of the total. In addition to unburned
hydrocarbons, exhaust emissions also include carbon
monoxide and nitrogen oxides.
The remaining 20% comes from the third and fourth
sources ... the fuel tank and the carburetor . . .
where evaporation goes on all the time.
A single car doesn't add much to air pollution. Only
about one-tenth of one percent of the engine ex-
haust is unburned hydrocarbons. But when hun-
dreds of thousands of cars are operating in a
congested area, it all adds up.
The automobile manufacturers undertook to solve
their own part of the air pollution problem, and
many scientists and engineers have put in much time
and effort to lower the level of hydrocarbon emis-
sions.
Crankcase emissions have been virtually eliminated
by the development of the PCV, or Positive Crank-
case Ventilation system.
To reduce exhaust emissions, General Motors has
developed the CCS, or Controlled Combustion
System . . . and the AIR, or Air Injector Reactor
system. Other manufacturers have similar systems
with different names. These systems reduce exhaust
emissions to below the required standards ... 275
parts per million by volume for hydrocarbons, and
1.5% by volume for carbon monoxide.
To control evaporation from the fuel tank and the
carburetor is not easy, and the automotive engineers
continue to work on the problem.
In the future, the emission control standards will
continue to change, and the automotive engineers
will continue to improve their emission control
systems to meet the new requirements.
Our job is to make sure the present systems con-
tinue to do the work they were designed to do.
Figure 1
-------
CRANKCASE EMISSION SYSTEMS
There are four reasons why some of the burned and
unburned gases from the combustion chamber enter
into the crankcase (Fig. 2):
suck out the undesirable crankcase fumes into the
atmosphere. Outside air entered the crankcase
through a vented oil filler cap.
1.
2.
3.
4.
Figure 2
High combustion chamber pressures.
Necessary working clearance of piston rings
in their grooves.
Normal ring shifting that sometimes lines up
clearance gaps of two or more rings.
Reduction in ring sealing contact area with
change in direction of piston travel.
There are two reasons why these blow-by gases of
combustion must be removed from the crankcase:
1. To prevent oil dilution.
2. To prevent the formation of sludge.
For many years a road draft tube system (Fig. 3)
was used to eliminate blow-by fumes from the
engine crankcase. In this system, the vacuum created
at the outlet of the road draft tube would simply
The road draft tube system left much to be desired.
It was ineffective for crankcase ventilation purposes
at low speed, and also contributed to air pollution.
OPEN PCV SYSTEMS
Various types of controlled crankcase ventilation
systems were installed on some cars as early as 1961,
and they became common on the majority of cars in
1963. Although there were basic differences in these
early systems, they all essentially used manifold or
induction system vacuum to withdraw blow-by
fumes from the crankcase and recirculate them into
the combustion chamber, along with the air fuel
mixture delivered by the carburetor.
Between 1963 and 1967, the most common method
used to control crankcase emissions was an open
positive crankcase ventilation system (Fig. 4). In a
INTAKE
MANIFOLD
• FRESH AIR
¦CRANKCASE VAPORS
• FRESH AIR PLUS
CRANKCASE VAPORS
p.c.v.
VALVE
V-8 OPEN
Figure 4
COMBINATION OIL FILLER CAP
AND VENTILATION AIR INLET
ROAD DRAFT
/TUBE
' FRESH AIR
• CRANKCASE CASES
~ FRESH AiR PLUS
CRANKCASE GASES
AIR FLOW PAST BASE
OF ROAD ORAFT TUBE
Figure 3
typical installation, this system utilizes a PCV or
control valve in the engine valve cover, and a hose
that connects the PCV valve to an intake manifold
vacuum opening. With some applications, the PCV
valve may be in a crankcase opening at the top of
the engine block, or at the intake manifold end of
the connecting hose. Other applications use only a
fixed orifice in place of a PCV valve.
Vented oil filler caps are characteristic of open PCV
systems. Under normal engine operating conditions
with an open PCV system, outside air which has
entered through the vented cap, plus crankcase
fumes, are drawn into the intake manifold and
burned in the combustion chamber. Under heavy
-------
acceleration, manifold vacuum decreases and crank-
case pressures build up. With these circumstances, a
portion of the crankcase fumes are forced back out
through the vented oil filler cap. For this reason, an
open PCV system only partially controls crankcase
emissions.
CLOSED PCV SYSTEMS
All 1968 and later model cars are equipped with a
closed positive crankcase ventilation system. Gener-
ally, it utilizes the same components as the open
system, with the following exceptions (Fig. 5):
==> FRESH AIR
——* CRANKCASE VAPORS
=~ FRESH AIR PLUS
CRANKCASE VAPORS
Figure 5
1. In place of a vented oil filler cap, an air
intake hose is connected between the carbu-
retor air filter and a crankcase opening in
the valve cover.
2. Sealed oil filler and dip stick caps are used.
3. A flame arrester is used in those installations
where air is supplied from the clean air side
of the carburetor air filter.
4. A separate PCV air filter is used when the
inlet air hose is connected to the unfiltered
side of the carburetor air cleaner. This filter
is either in the periphery of the carburetor
air filter, or at the point where the inlet air
hose connects to the valve cover.
Under normal engine operating conditions, the
closed PCV system functions in the same manner as
the open system, except that air enters the crank-
case through the inlet hose connected to the carbu-
retor air filter. However, under heavy acceleration
conditions, any excess vapors from the crankcase
flow back up through the air inlet hose to the carbu-
retor air cleaner. At this point, they mix with
incoming air, flow through the carburetor, and are
rebumed in the combustion chamber. Backup fumes
cannot escape from the system.
In effect, the closed positive crankcase ventilatio
system provides almost 100% control of crankca;
emissions.
PCV VALVE OPERATION
The PCV valve assembly consists of a valve spring,
valve plunger, and a two-piece, crimped outer vah
body (Fig. 6). The function of the valve assembly
VALVE SPRING VALVE BODY
Figure 6
to meter the flow through the system according 1
the various modes of operation . . . idle, acceler
tion, cruise.
The action of the valve plunger is governed by tt
intake manifold vacuum, and by the valve spring.
Figure 7
During periods of deceleration and idle or lc
speed, manifold vacuum is high (Fig. 7). This hi;
vacuum overcomes the force of the valve spring, a;
the plunger bottoms in the manifold end of t:
valve housing. Because of the valve constructic
this restricts, but does not completely stop the flc
of crankcase vapors to the intake manifold.
-------
When the engine is lightly accelerated or operated at
constant speed, intake manifold vacuum is less than
at idle. During this mode, the spring force equals the
vacuum pull, and the plunger assumes a mid-position
in the valve body. More crankcase vapors now flow
into the intake manifold (Fig. 8).
DUAL ACTION VALVE
There is one additional type of valve unlike the
plunger type that is referred to as the dual action
valve. It was used on several years production of
Oldsmobile. It functions as follows (See Figure 10).
Figure 8
In the event of a backfire, Fig. 9, the valve plunger is
forced back and seated against the inlet of the valve
body. This prevents the backfire from traveling
through the valve assembly into the crankcase. If the
backfire were allowed to enter the crankcase, it
could ignite the volatile blow-by gases. The plunger
DUAL ACTION VALVE SYSTEM
Figure 10
At low rpm operation, unburned hydrocarbons are
drawn into the intake manifold via valve opening (a)
connecting tube (b), and orifice (c), at the carbu-
retor base plate.
AIR CLEANER
CONNECTION
CRANKCASE
CONNECTION
Figure 11
Figure 9
is also seated when the engine is off and there is no
manifold vacuum.
It should be noted that additional air is permitted to
enter the intake manifold when PCV is used. How-
ever, the carburetor used with this system is cali-
brated to compensate for the air plus the blow-by
gas that enters the intake manifold from the crank-
case. For this reason, it should be remembered that
PCV valves are carefully sized for each engine.
At high engine rpm, a slight vacuum occurs at (d), a
slight blow-by pressure occurs at underside of check
valve (f) (See Figure 11). This combination ot vac-
uum and pressure, raises the check valve off seat,
allowing the additional blow-by to flow into the air
cleaner. At this time both the fixed orifice and
check valve are in operation.
•vC.1 ENGINE OFF OR BACKFIRE k
NO FLOW
. 7 "TSTS
NO MANIFOLD
VACUUM
PLUNGER IN CLOSED POSITION
.5$ 33
-------
PRACTICAL CHECK OF PCV SYSTEMS
If excessive sludging of the valve occurs, it will not
operate, and the valve passage may be closed. This
will cause high crankcase pressure at highway
speeds. This pressure can cause the engine to blow
out oil through the air intake or the engine seals and
gaskets.
A plugged system will definitely cause a rough idle.
A quick check to see if rough idle is caused by the
PCV valve is to:
1. Connect tachometer to the engine.
2. Start the engine and adjust idle.
3. Clamp off the hose that goes from the valve
to the carburetor base.
4. If the ventilation system is working prop-
erly, the engine rpm will drop about 30 to
50 rpm. You should be able to hear the
valve click shut when clamping off the line
and releasing it several times.
There will be no change in engine rpm if the valve or
hoses are sludged up and restricted.
TESTING PCV SYSTEMS
It is generally recommended that PCV systems (Fig.
12), be tested during the first four mohths or 6,000
miles of operation. Thereafter, a system should be
checked during engine tune-up, or whenever rough
engine performance warrants it.
It is best to check a PCV system with a tester de-
signed for the purpose. The AC CT-3 is a typical
tester. It reports the condition of the system by
color ... red for danger, orange for caution, green
for okay. The valve can be tested separately. Com-
plete testing procedures and specifications are a part
of the instructions packaged with the tester.
Figure 12
SERVICING PCV SYSTEMS
PCV systems must be maintained in proper workin
order to insure minimum crankcase emission, as we
as good engine performance. Generally, manufactu
ers recommend the following procedures at periodi
tune-up intervals, or every twelve months or 12,00
miles of operation:
1. Replace the PCV valve assembly ever
twelve months or 12,000 miles.
2. Replace any replaceable type filters. Cleai
and re-oil the cleanable type filters.
3. Inspect, clean, and ... if necessary . .
replace all hoses, tubes, and fittings in th
PCV system.
Disassemble and wash all components in a suitabl
solvent, and blow out gently with compressed air. I
the system is not excessively dirty, cleaning with
spray type solvent is acceptable. Extremely dirty o
deteriorated hoses should be replaced. Use only th
recommended oil and gas resistant hose.
EXHAUST EMISSION SYSTEMS
One of the approved exhaust emission control
methods gets results through the use of modified
carburetion, revised ignition timing, and hotter ther-
mostats (Fig. 13). The carburetor calibration is
changed to provide a leaner mixture, the spark cali-
bration is changed to provide retarded initial timing,
and the hotter thermostats permit higher coolant
temperatures. These factors . . . along with a ther-
mostatically controlled air cleaner . . . cause more
complete combustion and a reduction in the amount
of unburned hydrocarbons and carbon monoxide.
The General Motors name for this control method is
Controlled Combustion System (CCS). Other manu-
facturers have different names.
Figure 13
TESTER
WINDOW
P.C.V. SYSTEM
FRESH AIR
llNltT PLUGGED
-------
For purposes of explanation and understanding, we
svill describe the CCS and its various components.
They are typical of units found on other instal-
lations, and even though they may vary in appear-
ance, they function in a very comparable manner.
Many different components will be found on various
CCS installations. Basically, each engine and trans-
mission combination has different control require-
ments.
Manufacturers use whatever unit or combination of
units is required to control their various engine
applications. Generally speaking, engines used with
standard transmissions require more control compo-
nents than engines used with automatic transmis-
sions. Also ... for any given engine application, the
use of control components may vary from one
model year to another.
When you are familiar with the function of each
individual type of control component, you will
know how to relate its use to the different cars that
may come to your attention. Here are the principal
components that you should know.
VACUUM SPARK ADVANCE
For many years, two sources of vacuum have been
utilized to control the vacuum operated advance
unit on the distributor, and thereby vary spark
timing in relation to engine load (Fig. 14).
>' tl ^/DIAPHRAGM
LINKAGE
^VPORTED" breaker plate
TIMED VACUUM
M SPARK ADVANCE
J I AT IDLE
^VDIRECT"
FULL SPARK
AOVANCE AT IDLE
Figure 14
1. "PORTED" vacuum provides timed vacuum
spark advance at idle. In this case, a calibrated
port is located in the throttle bore just above
the throttle valve. It is connected by a
vacuum line directly to the distributor
vacuum advance unit. In the curb idle posi-
tion, the throttle valve is below the spark
port. Consequently, no vacuum is applied to
the advance unit, and the spark advance
remains in the retarded position.
As the throttle valve is opened and engine
speed increases, the resulting vacuum is
applied to the vacuum advance unit, causing
the spark to advance for normal operation.
2. "DIRECT" manifold vacuum provides full
vacuum spark advance at idle because the
vacuum advance line is connected to a port
either in the throttle bore below the throttle
valve or in the intake manifold.
Some emission controlled engines use only "ported"
vacuum advance. Others use both "ported" and
"direct" manifold vacuum for more effective emis-
sion control under various engine operating condi-
tons.
TYPICAL VACUUM CONTROL CIRCUIT
A typical vacuum control circuit (Fig. 15) includes a
combination of the different types of control units
that might be found on different engine applica-
tions. Remember that not all control units will be
found on all engine applications. However, when
you are familiar with the basic function of each
unit, you will have no problem in adapting your
knowledge to any particular car.
Following are descriptions of different units that are
utilized to control vacuum spark advance for various
engine-transmission combinations.
Figure 15
DUAL ACTION VACUUM ADVANCE - RETARD
CONTROL
Some distributors used with emission controlled en-
gines have a dual acting vacuum advance-retard
mechanism. Its purpose is to provide retarded timing
during idle and coast down or deceleration condi-
tions. With full manifold vacuum applied to the re-
dual action vacuum
ADVANCE-RETARD CONTROL
VACUUM ADVANCE
VALVE
THERMOSTATIC
VACUUM SWITCH
-------
tard side, the timing is approximately 5 degrees to 10
degrees below the initial timing setting.
Under part-throttle conditions, the advance side of
the dual action mechanism functions to provide
normal vacuum advance. Fig. 16 is used only to il-
lustrate the basic principles involved. In actual in-
stallations, both thermostatic and vacuum advance
valves may be used as part of the total vacuum con-
trol circuit. These units make it possible to route
direct manifold vacuum to the retard port and either
ported or direct manifold vacuum to the advance
port.
ADVANCE SIDE
RETARD SIDE
ADVANCE 0° RETARD
* I »
Figure 16
THERMOSTATIC VACUUM SWITCH
In most emission controlled engines, initial ignition
timing is slightly retarded, compared to previous
years. Engines with retarded initial timing tend to
run hotter at idle ... if allowed to idle for lengthy
periods. For that reason, many engines are equipped
with a thermostatic vacuum switch (Fig. 17), lo-
cated in the engine coolant jacket near the front of
the engine. Valves may have either three or five hose
DISTRIBUTOR
VACUUM
ADVANCE
CONNECTION
CARBURETOR
VACUUM
INTAKE
MANIFOLD
VACUUM
PLUNGER
THERMOSTATIC VACUUM SWITCH
Figure 17
connections, depending on
circuit in which it is used.
the vacuum contro
When the coolant temperature reaches approxi
mately 220 degrees F, the valve switches the vacuun
source from ported to direct manifold vacuum , .
and the distributor vacuum control advances tht
spark timing to speed up the engine. This results ir
lower combustion chamber temperature, and alonj
with higher fan speed, cools down the engine. Afte
the engine has cooled down, the thermostatic switel
returns to ported vacuum, and the timing returns tc
the normal retarded position.
VACUUM ADVANCE VALVE
Some engine applications use a vacuum advance
valve to provide better combustion during
"coasting" conditions, when the throttle is closed
and direct manifold vacuum is high. In operation
the valve switches from ported vacuum, and applies
direct manifold vacuum to the distributor to ad
vance the ignition timing. This results in more com-
plete combustion of the fuel charge (Fig. 18).
TO MANIFOLD VACUUM
TO DISTRIBUTOR
VACUUM ADVANCE VAIVE"
Figure 18
IDLE STOP SOLENOID
Because of the higher idle speeds used with emissioi
control systems, the possibility of dieseling exist,
after turning off the ignition on certain vehicles. T<
alleviate this condition, an idle stop solenoid is usee
on some cars (Fig. 19).
Figure 19
I DIE SPEED
SOLENOID "
LOW IDLE i
ADJUSTMENT]
SCREW I
IDLE ADJUSTMENT SCREW
-------
The solenoid eliminates dieseling tendencies by
allowing the throttle valve to close beyond the nor-
mal curb idle position when the ignition switch is
turned off.
In operation, the solenoid is energized whenever the
ignition switch is turned on. The plunger of the sole-
noid serves as a stop for the carburetor throttle
lever. As a result, normal idle speed adjustment is
obtained by turning the solenoid plunger screw "in"
or "out".
When the ignition switch is turned off, the solenoid
plunger retracts and allows the throttle lever to
move toward the closed position until it strikes the
carburetor throttle stop screw. On these applica-
tions. two idle speed adjustments must be made . . .
one with the solenoid energized, and another with
the solenoid de-energized. Refer to the United Delco
60A100-1 tune-up specifications for the correct idle
speed adjustment procedures.
THERMOSTATICALLY CONTROLLED
AIR CLEANER
General Motors cars equipped with CCS incorporate
a thermostatically controlled air cleaner, designed to
keep air entering the carburetor at approximately
100 degrees F when underhood temperatures are
less than 100 degrees F. By keeping the air at this
temperature, carburetor icing can be minimized,
engine warm-up can be improved, and . . . finally .. .
the carburetor can be calibrated for leaner fuel air
ratios that will reduce hydrocarbon emission. This
system is known as the AC Auto Thermae (Fig. 20).
Figure 20
The system basically consists of a temperature sen-
sor, vacuum operated air control motor, hoses, and
pipes. Also included is the necessary shrouding
around the exhaust manifold ... a heat stove that
supplies heated air to the carburetor. The sensor is
located in the cleaner body, on the clean air side of
the air filter.
In operation, the sensor bleeds varying amounts of
air . . . depending on the temperature ... to the
vacuum motor. The motor, through its linkage, pro-
vides for four modes of operation.
1. Static mode (Fig. 21). When the engine is
not in operation, the control damper assem-
bly will be so positioned that the snorkel
tube passageway will be open, and the hot
air pipe will be closed. This is the result of
the absence of vacuum in the diaphragm
chamber of the vacuum unit, and the effect
of the diaphragm spring which pushes the
diaphragm and its linkage downward.
2. Hot air delivery mode (Fig. 22). When the
Figure 22
engine is started, and underhood tempera-
ture is less than 85 degrees F*, engine vac-
uum is applied to the vacuum chamber in the
motor, via the connecting hoses and the
-------
sensor. The sensor air bleed valve at this
time is closed. The vacuum overcomes the
force of the diaphragm spring, and the dia-
phragm and linkage are pulled upward. In
turn, the control damper assembly is posi-
tioned to shut off the flow of cold air, and
permit hot air to enter the air cleaner
through the hot air pipe.
Should the engine suddenly be heavily
accelerated while in the hot air mode, the
vacuum level in the system will drop to a
very low level. In turn, the motor diaphragm
spring will push the diaphragm and linkage
downward, thus positioning the control
damper assembly to permit air to enter the
air cleaner through the snorkel tube.
3. Cold air delivery mode (Fig. 21). When the
temperature of the air at the sensor is above
128 degrees F**, the sensor bi-metal spring
relaxes and moves downward. This allows
the sensor air bleed valve to open. A suffi-
cient amount of air will bleed into the
motor vacuum diaphragm chamber, drop-
ping its vacuum level. The diaphragm spring
will force the diaphragm and its connecting
link downward, placing the control damper
assembly so as to open the cold air passage,
and close the hot air pipe, permitting cold
air to enter the air cleaner.
4. Regulating mode (Fig. 23). At temperatures
CHECKOUT AND SYSTEM SERVICING
Make a visual inspection of the system, checking foi
loose, kinked, or deteriorated hoses. Repair or re-
place as required.
QUICK CHECK
1. Start test with engine cold, with air cleane
at a temperature below 85 degrees F*. If th<
engine has been in recent use, allow it t<
cool.
2. Observe the damper position before startin]
the engine. If the position of the snorke
tube requires it, use a mirror. The dampe
should be in the cold air delivery mode.
3. Start the engine and allow it to idle. Imme
diately after starting the engine, the dampe
should be in the hot air delivery mode.
4. As the engine warms up, the damper wi]
move toward the cold air delivery mode
while the air cleaner becomes warm to th
hand.
5. The system is operating normally as de
scribed above. If the air cleaner fails t
operate as above ... or investigations of th
reported complaint fail to establish a cause
or the correct operation of the air cleaner i
still 'n doubt . . . proceed to the system
operational test.
between 85 degrees F* and 128 degrees
F**, varying amounts of air are bled into
the system, depending on the exact temper-
ature at the sensor unit. This results in a
vacuum level and control damper assembly
position required to maintain carburetor air
temperature at from 85 degrees F* to 128
degrees F** when underhood temperatures
are below this range.
OPERATIONAL TEST
1. Start test with the air cleaner at a temper!
ture below 85 degrees F*. If the engine ha
been in recent use, allow it to cool down.
NOTE: At temperatures above that specif
ed, this test cannot be performed. Howevei
make certain the damper assembly is in th
cold air delivery mode. With the air cleane
in position, secure a temperature gauge nex
to the sensor a half-hour before proceedin
to Step 2. Install air filter cover. Do nc
install wing nut.
2. Start engine. When the control dampe
assembly begins to open the snorkel tub
passageway, observe test gauge temperatun
It must read between 85 degrees F and 11
degrees F***.
3. If the system fails to operate the dampt
assembly at the temperature indicated, pr<
ceed to the vacuum motor check.
-------
VACUUM MOTOR CHECK
1. With the engine shut off, the position of the
control damper assembly should be in the
cold air delivery mode.
2. To determine if the motor is operable, apply
at least nine inches of vacuum . . . either
from the engine or an independent source ..
to the vacuum fitting on the motor.
3. The control damper assembly should close
the cold air passage as long as vacuum is
applied. The hot air pipe will be open.
4. If the vacuum motor fails to operate the
control damper assembly with the direct
application of vacuum, first check to deter-
mine if the motor linkage is properly con-
nected to the door, or if a bind is present. If
the linkage is found satisfactory, then motor
replacement is indicated.
5. If the motor check is found to be satisfac-
tory, then sensor replacement is indicated.
Sensor and vacuum motor assembly replacement
packages contain detailed instructions and replace-
ment procedures. The damper door is not ser-
viceable. The air cleaner assembly must be replaced
if the damper door is defective.
FOOTNOTES
* Except for Buick V-8 (95 degrees) and GMC V-6 (66 degrees).
** Except for Buick V-8 (138 degrees) and GMC V-6 (108 degrees).
*** Except for Buick V-8 (95 degrees to 125 degrees) and GMC V-6 (66 degrees to 100 degrees).
FORD IMPROVED COMBUSTION SYSTEM (IMCO)
The IMCO system is similar to the GM CCS system
previously discussed. The following additional
special notes apply.
1. Some carburetors use special external lim-
iter caps on the idle mixture screws which
limit the idle adjustment range, prohibiting
rich idle mixture adjustments. Others use
fixed internal orifice limiters at the base of
the idle mixture screws.
2. Both "IMCO" and "Thermactor" use a tem-
perature controlled carburetor air intake sys-
tem, as shown in Ford Motor Company's
views (Figures 24 thru 27). It is similar to
the AC Auto Thermae. Basically the system
consists of a valve plate and spring assembly
(air door) thermostatic bulb and vacuum
override motor. (See Figure 24).
The system operates on the principle of expansion
and contraction (according to temperature) of the
-thermostat which in turn operates the valve plate
(door) through its range of control. Generally a
vacuum override motor is connected to engine
vacuum. Its function is to overcontrol the ther-
mostat providing a mixture of hot and cold air dur-
ing heavy acceleration periods. The three modes of
operation are shown in Figures 25-26-27.
Warm up. Duct and valve assembly in
Heat-on position (Fig. 25).
Figure 24
Figure 25
-------
QUICK CHECK OF THE DUCT
AND VALVE ASSEMBLY
WITHOUT OVERRIDE:
With the duct assembly installed on vehicle, cold
engine and not running and a temperature of less
than 100° in engine compartment, the valve plate
should be in the "heat-on" position.
WITH OVERRIDE:
With the duct assembly installed on vehicle, cold
engine and not running and the temperature of
less than 100° in engine compartment, the valve
plate assembly should be in the one half heat-on
position.
Cold Duct and valve assembly in
acceleration. Partial Heat-on position (Fig.
26).
Start engine - it should go to the "heat-on" position.
(For both with or without vacuum override.)
As the engine warms up and the engine compart-*
ment temperature exceeds 100° the duct and valve
assembly should move to the "heat-off position.
If the duct and valve assembly does not meet these
requirements, check the assembly for binds, pooi<
vacuum connections and defective vacuum motor.
For detached check out of the thermostatic temper-
ature bulb, refer to the Ford Motor Service Manual^
Warm engine. Duct and valve assembly in
Heat-off position (Fig. 27).
TO AIR CLEANER
COlO All
tfjia WARM Alt
4m HOT All
TO AIR CLEANER
-------
PROCEDURE CHECK SHEET
Name Make of Vehicie Year_
Address Model:
Telephone No 4 cyl. CD 6 cyl. CD 8 cyl. CD
.'•V "V
AUD ADJUSTMENTS
liPCLJ AMD EXHAUST
riser *c).9fc!'!w&v.efc£ifcr
• Se/v'ts P.'CV. drtd
^^.cctS"ur-?10f ar;t>cwb»st'?r. shelter
¦S&wra2«S
•Te& .f«9l pj^^Tim'fr^^pftroxinjeJwy,-6w; jwJ.-m*,
$^*4 -i&#
- • . • I . • .• v-. •-: >, ¦:• •• • •-
£$ :&qf>>?- -
^.;ri;ty,„;,
P clscne* w.Ves.'. :¦* .. '¦¦ f'; : •'" *\ ' ¦ -i£'
.. •-'' >' '+:.y ... V -" ". s. ¦ '. '-v
i«cfc'VrvCMi^^agt'^nlpd4* C--?: .¦¦***'.¦ V
Sttjif *. ft 'fti'xh/fe ^ . > / .«'.
SYSTgfA
ficctrcin.
CUSTOMER'S STORY
Mileage since last fune-up
Mileage since last carburetor overhaul-
Customer Performance Complaints:
Poor Acceleration
-Rough ldle_
-Stalls
Engine Knocks or Pings
Hard Starting Hot Cold High Speed Miss.
Preventive maintenance tune-up desired
(No specific performance complaints)-
I. BATTERY AND CABLES
1. Cieon battery, battery and cable terminals, battery carrier and
hold downs. Q
IV. SPARK PLUGS
1. Replace.
2. Clean and regap—Gap Specifications-
V. DISTRIBUTOR AND IGNITION CIRCUIT CHECKS
1. Inspect cap and rotor.
2. Check centrifugcl and vecuum advance units.
3. Check condition of primary and secondary wiring.
4. RepLce contact points and condenser as required.
5. Lubricate as required.
2. Check battery condition and state of charge.
Defective CD Satisfactory
Discharged Q
II. CRANKING MOTOR AND CIRCUIT
1. Clean and tighten terminal connections. CD
2. Operates at satisfactory speed and sound. CD
3. Electrical check—Unsatisfactory CD Satisfactory
III. ENGINE MECHANICAL CONDITION
(Determined by compression or cylinder balance test, etc.)
Cylinder Check
1
2
3
4
5
6
7
8
giv* - ; . j ••
0 .. . , r-i c .¦ t . n Rfcj-'.i'.yi-Oiojgo fa<*»»ery as <<*quire"k - " < t »•- AS
If questionable,
Suggest use of carburetor and combustion chamber condi
tioner as partial corrective measure
WE USE GENUINE UNITED DELCO PARTS
MI-226
Printed in U.S.A.
Figure 28
-------
ENGINE TUNE-UP
PROCEDURE
Engine tune-up means different things to many people. To the car owner it is a term that indicates good
overall vehicle performance. To the engineer it infers the technical aspect; supplying the required electrical
voltage and fuel-air ratio so that the engine will run smoothly at all speeds and loads. To the practical tune-up
specialist, tune-up means performing a series of checks, tests and adjustments that will restore original
standards of performance to the engine. Finally engine tune-up, properly performed, means optimum auto-
motive emission control.
A definite relationship exists between emission controls and engine tune-up. An engine that is out-of-tune
after many miles of operation can result in failure of the emission controls to properly perform their job.
Malfunctioning emission controls can cause poor engine performance. Thus, car owner satisfaction is depen-
dent on thorough testing and service of all components related to both performance and emission control.
The purpose of this section is to provide a complete step-by-step pictorial tune-up procedure as a guide for the
practical tune-up specialist. Each step is related to the "Power Service" Procedure Check Sheet (Fig. 28) that
is available for use in your daily tune-up work. In this No. 1 manual we will be concerned with only the first
half of the tune-up procedures normally performed. You will find the remaining half in the No. 2 Power
Service Manual.
Knowledge - Recognition - Understanding
It is not within the scope of the "Power Service
Manuals" to provide you with a complete back-
ground in basic principles of carburetor, electrical
and engine components that are essential to engine
tune-up. However, there are certain fundamentals
with which you should be familiar:
A. Tune-up cannot be performed without an
adequate understanding of the basic engine as
well as the various units and systems that feed
the engine. In contrast to what the term implies,
most operations in engine tune-up are per-
formed on carburetor and electrical compo-
nents (Fig. 29).
Figure 29
B. Compression, ignition and carburetion are often
referred to as the basic requirements of tune-up.
A knowledge of how these three ingredients are
coordinated through the action of the crank-
shaft, camshaft, cylinder, carburetor and distrib-
utor are essential for anyone interested in
tune-up (Fig. 30).
CARBURETION IGNITION
-cii
Figure 30
C. Five important areas have to be considered in
tune-up. Good engine mechanical condition is a
prerequisite without which tune-up is imprac-
tical. If engine is tunable, all recommended
operations have to be performed in the
cranking, ignition, fuel and charging systems for
complete tune-up.
-------
D. Each major area in tune-up requires (Fig. 31):
I. Battery and Cables
1. VISUAL INSPECTION for deterioration
and wear.
2. CLEANING of corrosion, oii and dirt at
critical Doints.
3. REPAIR OR REPLACEMENT of needed
parts.
4. TESTING each circuit or system for hidden
defects.
5. ADJUSTING accurately to all tune-up
specifications.
5 TYPES OF OPERATIONS
TESnNG
<0
INSPECTION
REPLACEMENT
CLEANING
ADJUSTMENT
Figure 31
LISTEN TO THE CUSTOMER'S STORY
Before proceeding with an engine tune-up, it is
important to obtain factual information from an
owner regarding the past service history of his car
and any performance problems he might have
encountered. Record this information in a Power
Service Procedure Check Sheet. Although an owner
may not know what is wrong with his car, the infor-
mation he provides will be invaluable to you in cor-
recting a specific complaint which may or may not
be related to engine tune-up. Remember that any
specified problem has to be diagnosed and correc-
ted. The owner may judge the quality of your
tune-up on this one point (Fig. 32).
' Many owners will want only a preventive mainte-
nance tunc-up and will specify no particular prob-
lems. In either case following the complete Power
Service Procedure will be your insurance that your
tune-up will be done right the first time and there-
fore no costly come back or repeat work.
1. Clean and Visually Inspect Battery and
Cables - The external condition of a battery
plus good cables and tight corrosion free
connections all contribute to battery perfor-
mance. Additionally, its appearance is a
factor in customer judgment of a quality
tune-up (Fig. 33).
Make a visual inspection of the battery for
cracked case and covers. Check cables for
corroded terminals and frayed or damaged
insulation. If the battery or cables show
serious signs of deterioration, they should
be replaced.
Remove cable terminals from battery and
clean battery and terminals with a solution
of baking soda and water. Remove oxida-
tion from cable terminals and battery posts
with a wire brush. After cables are replaced
on battery, apply a film of grease to ter-
minals to retard corrosion. Check battery
hold-down for correct tightness. Check and
adjust electrolyte level.
Caution - When connecting battery cables,
always connect the ground cable last.
OVERFILLING
DIRT
FRAYED OR
BROKEN CABLES
CORROSION /
SEALING
COMPOUND
LOOSE
HOLD-DOWN
CELL
CONNECTOR
CORROSION
Figure 32
Figure 33
2. Test Battery - The accuracy of many checks
and electrical tests in tune-ups depends
upon the condition and state of charge of
the battery. It should be thoroughly tested
early in the tune-up procedure. Tne ability
of the battery to render trouble-free service
can best be checked with a 421 tester and a
hydrometer (Fig. 34).
Caution - Never deliver a tuned-up car with
a battery in a low state of charge.
-------
Figure 34
II. Cranking Motor and Circuit (Fig. 35)
1. Check ail circuit connections at cranking
motor solenoid or magnetic switch. Clean
and tighten if necessary.
2. Ground coil distributor terminal with a
jumper wire and crank engine through 8-10
revolutions, observing the cranking speed
and sound of the cranking motor. If the
speed and sound are normal, omit Check
No. 3. If speed and sound are abnormal,
proceed to Check No. 3.
3. Test Cranking Motor and Circuit - Two vol-
tage tests, one at the cranking motor battery
terminal and one at the switch terminal, will
give the best indication of both cranking
motor and circuit conditions.
With ignition switch in the cranking posi-
tion, voltage at the solenoid or magnetic
switch battery terminal should be no less
than 8.6 volts. (Where accessibility is a
factor, a voltage test at the battery terminals
will j>uffice). Voltage at the solenoid or
magnetic switch terminal should be no less
than 7.7 volts.
Remember that you have checked the bat-
tery condition and cleaned the battery post
cable connection earlier in the tune-up pro-
cedure. These actions will have eliminated
the major sources of trouble in the cranking
motor circuit.
Figure 35
III.Engine Mechanical Condition (Fig. 36)
A compression test gives a good indication
of engine mechanical condition. The com-
pression of the lowest cylinder should be at
least 75% of the highest cylinder. Low com-
pression on one or more cylinders indicates
defective rings, gaskets or valves. Excessive
carbon build up on valves and in the com-
bustion chamber may also cause uneven
compression readings. X66 combustion
chamber conditioner is recommended for
carbon removal.
A cylinder balance test will also give a good
indication of engine mechanical condition.
Irrespective of the type of test used the
engine mechanical condition should be
determined early in the tune-up procedure.
If serious engine mechanical defects are
noted, advise the owner before proceeding
with the tune-up.
-------
IV.Spark Plugs (Fig. 37)
1. Visually inspect spark plugs for cracked
insulation, damaged threads and eroded
electrodes. Replace as required. Use manu-
facturers specified part numbers, heat range
and gap setting.
2. If spark plugs are in condition for re-use,
clean, file end of center electrode flat to
restore sharp corners and re-gap to specifica-
tions. Use a new gasket.
Make sure spark plug holes and gasket seat
are free of carbon and rust.
Figure 37
V. Distributor and Ignition Circuit Checks (Fig. 38)
1. Check distributor cap and rotor for cracks,
chips and carbonized paths which will allow
high voltage leaks to ground. Such defects
require replacement. Wipe cap inside and
outside with clean solvent-dampened cloth.
Inspect towers and electrodes for corrosion
and oxidation. Remove same with special
wire brush. Check carbon button in center
of cap for wear or electrical arcing deteri-
oration.
Check rotor spring for proper tension and
contact with carbon button in distributor
cap.
Replace contact set and condenser as re-
quired. New contacts should be properly
aligned and leads should be positioned to
avoid interference with cam, contact points
or rotor. Any frayed leaks should be re-
placed. Place a small amount of high tem-
perature cam lubricant on the breaker cam
surface or replace cam lubricator if so equip-
ped. On internal adjustment distributors,
apply two or three drops of oil to felt wick
under rotor.
Figure 38
2. The mechanical action of centrifugal
advance mechanisms can be checked by
turning rotor in direction of normal rota-
tion. The action of the weight springs
should enable it to snap back quickly and
freely to normal position (Fig. 39).
Figure 39
Mechanical action of vacuum advance
mechanisms can be checked by turning dis-
tributor plate or complete distributor in
opposite direction to normal shaft rotation.
TTiey should return to normal position
freely and quickly (See Fig. 40).
MOVABLE PLATE TYPE FIXED PLATE TYPE
Figure 40
-------
A more complete check of the centrifugal
and vacuum advance units can be made with
a power timing light. This check will indi-
cate whether total timing advance is within
specification at the 2000 to 2500 RPM
range.
3. The physical condition and connections of
all primary and secondary ignition cables
should be checked. Make sure all primary
connections are clean and tight and that
insulation on both primary and secondary
cables is not frayed, damaged or oil soaked
(See Fig. 41).
When removing secondary cables from coil
tower, distributor cap or spark plugs, the
insulating boots should be loosened with a
slight rotating action. Then pull out cable
while holding base of insulating boot. After
replacement all cables should be firmly
seated in cap and coil towers.
Figure 41
Use of cable part numbers specified by manu-
facturer will insure proper ignition perfor-
mance and radio frequency suppression.
%¦ IDLE SPEED: f" . SOLENOID" SCREW ;.',> JCARBURETOR SCRI
dgj- Aula. TnmWUinVTOIVedrcW ^./^. SOOrpm :
Manual TnmMlS^fei 'iWZ' 650roatf»3
vv'.y a. rmmft-m
, Port, Me. 9ZW14?r»rR<*»3;> (See SERVICE MANUAL for Instructions.K 'jWP«mtiac Mofot Dfcr„ GMC.
THIS ENGINE IS DESIGNED TO REDUCE EXHAUST EMISSIONS.
PROPER MAINTENANCE AND ADJUSTMENTS ARE ESSENTIAL
TO CONTINUED EFFECTIVENESS
DISTRIBUTOR SETTINO-O* TDC @ 600 RPM 0WELL-30* (POINT GAP-.0t«")
SPARK PLUG GAP—.030" IDLE SPEED—400 RPM IN NEUT (AIR COND. OFF)
IDLE MIXTURE ADJUSTMENT PROCEDURE: *
1. WITH ENGINE AT NORMAL OPERATING TEMPERATURE AND WITH AIR CLEANER
ON. AOJUST MIXTURE SCREWS TO BEST IDLE WITH SPEED AT 630 RPM
2. FINALLY, LEAN IDLE MIXTURE SCREWS EOUALLY (CLOCKWISE] TO REDUCE SPEED
TO NOT LESS THAN 600 RPM.
BUICX SHVICt MANUAL >OI ADDITIONAL INFORMATION MIT NO lUHIt COOi
fh b^stemIssio ns Epropm to "E°uce ~ ~—'
UJ and ADJUSTMENTS ARP m^'NTENANCE rnu
SStZ":. "Ci,7M -¦ **cuum ho»
®'»t.iwto, tinued "WCTIVbSsS TO L~~
ow»tc at y "
" "<*> 0*»-.aJ5- O'SCONNKTJO 4 ,luoofo
' if, 38"" »".*> USE RCGular fUEl
*S===r~-=
Figure 42
POWER SERVICE
MANUAL NO. 2
WILL CONTAIN THE SECOND HALF
OF THE COMPLETE ENGINE TUNE-UP
PROCEDURES
SPARK
PLUG
-------
TABLE OF CONTENTS
Introduction 34 3
Air Injector Reactor
System 344
AIR System Components and
Typical Installation 344
Basic AIR System
Operation 344
Components:
Air Pumps 34 5
2-Vane Pump 34 5
Centrifugal Filter 345
Pressure Relief Valve ... 346
3-Vane Pump 347
Diverter Valve 347
Check Valve and
Combustion Pipe
Assembly 348
System Variations 34 8
Servicing the AIR System ... 349
Checking the AIR System ... 349
Drive Belt 349
Air Injector Pump 34 9
Diverter Valve 349
Air Manifolds and Hoses 350
Page No.
Check Valve 350
Air Injector Tubes 351
AIR System Diagnosis 351
A. Pump Noisy 35]
B. Popping in
Exhaust System.... 352
C. Backfire in
Exhaust System.... 352
D. Backfire or Popping
in Inlet Manifold ... 352
E. Off Idle Hesitation
and Rough Idle .... 352
F. Rough Idle or
Surge 353
G. Engine Idle
Speed High
H. Engine "Diesels"
After Ignition Is
Turned Off 353
I. Overheated Exhaust
System 353
J. Deteriorated Supply
Hose 353
INTRODUCTION
Page No.
K. Constant Air
Noise 353
Chrysler CAP System . . . . . . 354
Vacuum Control Valve
Operation 354
Idle Speed and Mixture
Adjustment 355
Carburetor Vacuum Check. ..356
Vacuum Control Valve Tests 355
Vacuum Control Valve
Adjustment 357
Engine Tune-Up Procedure . .350
VI. Ignition Circuit Tests
and Adjustment . . . .359
IA. Voltage Checks. . 359
IB. Ignition Wave
Form Analysis . .359
VII. Manifold and Emission
System Service 362
VIII. Carburetor and Fuel
System Service 363
IX. Charging System 3 64
X. General Vehicle
Inspection 364
UMS Power Service Training Manual No. II, is an
extension of the information contained in Manual
No. I.
Power Service Manual No. I made you familiar with
typical crankcase and exhaust emission control
systems now required on all cars, according to
Federal law. It contains an explanation of the PCV
(Positive Crankcase Ventilation) system and the CCS
(Controlled Combustion System). Also included is a
description of the procedures performed during the
first half of a complete engine tune-up.
This Power Service Manual No. II goes forward from
that point. It includes a description of the basic
operating principles and the components for both
the AIR (Air Injector Reactor) and (CAP) Chrysler
systems, and includes the second half of the Power
Service tune-up procedures.
Manual No. I points out that crankcase emission
control systems function in much the same manner
on all makes of cars. When you understand a typical
system, you are prepared to service any similar
system. The GM CCS (Controlled Combustion
System) is also presented as typical of one type of
exhaust emission control system.
Manual No. II explains a typical GM Air Injector
Reactor (AIR) system, Ford and American Motors
have similar systems called the Thermactor and Air
Guard systems, respectively. Other manufacturers
also use basic Air Injection systems. All the systems
utilize the same type of components, even though
they have different external appearances. When you
understand the AIR system and its components, you
will easily recognize how the comparable systems
function.
Also included in this Manual is an explanation of the
Chrysler Cleaner Air System (CAS) or Cleaner Air
Package (CAP). These systems have many simila-
rities to the CCS system except that no hot air
cleaner is used.
Power Service Manual No. I told you that, all en-
gines equipped with a CCS-type exhaust emission
control system have these modifications:
1. Specifically calibrated carburetor
2. Specifically calibrated distributor
3. Generally retarded timing
4. Higher idle speed
5. Higher operating temperatures
This is true of engines equipped with an AIR-type
system, too.
-------
Like the CCS, the AIR system requires only limited
service. In most cases, a Power Service tune-up will
assure satisfactory exhaust emission control. That's
why the First Manual included the first half of the
regular tune-up procedures and why this Manual' pre-
sents the second half.
To test your understanding of the material pre-
sented, an examination paper is included with this
Manual. You are already familiar with the form, if
AIR INJECTOR
Combustion in the modern automotive engine has
been improved by use of the specifically calibrated
carburetor and distributor, by generally retarded
timing, higher idle speed, and higher operating tem-
peratures. However, it is still necessary to have a
supplementary method of reducing the amounts of
carbon monoxide and unburned hydrocarbons to
the low levels established by law.
The Air Injector Reactor system (Fig. 1) ac-
complishes that reduction by adding oxygen, in the
form of compressed air, to the very hot and highly
flammable gases released by the exhaust valves.
That's much like fanning dying embers, and the re-
sult is the same. The added oxygen causes the un-
burned hydrocarbons to ignite immediately, and the
reaction changes the exhaust emissions to harmless
gases, the by-products of nearly-complete com-
bustion.
Figure 1
you have completed the First Manual examination.
From each of the three possible answers, select the
one that you believe to be correct. Mark down your
choice and the page number where you located the
answer.
When you have successfully completed both exam-
inations, you will receive a diploma which will
assure your customers that you can perform United
Delco Power Service Tune-Up.
REACTOR SYSTEM
AIR SYSTEM COMPONENTS AND TYPICAL
INSTALLATION
The Air Injector Reactor (AIR) system is primarily
composed of an air pump, diverter valve, check
valve, air manifold or combustion pipe assemblies,
and connecting hoses and fittings. In a typical V-8
engine installation (Fig. 2), the air manifolds or
combustion pipes route the compressed air into the
exhaust manifolds.
DIVERTER VALVE AIR PUMP
Figure 2
With some engine applications, the air is carried to
the exhaust ports through a drilled passage in the
cylinder head. This eliminates the need for an ex-
ternal air manifold.
BASIC AIR SYSTEM OPERATION
In normal vehicle operation, the AIR system draws
-------
iltered air into the air pump, where it is com-
iressed. The compressed air is fed out of the pump
hrough the diverter valve, through the check valve,
nto the combustion pipe assemblies, and delivered
o the exhaust valve areas (Fig. 3).
"he compressed air mixes with the hot exhaust gases
n the cylinder head or exhaust manifold, and bums
lost of the carbon monoxide and hydrocarbons be-
are the gases leave the engine through the exhaust
ystem. Thus, the exhaust emitted at the taii pipe is
:>w in harmful ingredients that cause air pollution.
"he oxygen in the compressed air must be added at
he exhaust valve areas, because the gases cool down
o a non-flammable mixture by the time they enter
he exhaust system. There is a slight increase in
perating temperatures at the cylinder head or ex-
aust manifold, but it is not sufficient to cause con-
em.
pressing clean air for injection into the exhaust
manifold or cylinder head.
The only major differences between the two pumps
are that one has two (2) vanes and its own centri-
fugal air cleaner, while the other pump has three (3)
vanes and draws its fresh air supply either from the
clean air side of the carburetor air cleaner or from a
separate air intake filter.
2-VANE PUMP
Component parts of the 2-vane pump include (Fig.
4):
1. Pump housing
2. Centrifugal filter.
3. Set of two vanes, which rotate about the
centerline of the pump housing bore.
4. Rotor, which rotates on an axis different from
the axis of vane rotation. The rotor drives the
vanes, and is driven by the pump's pulley.
5. Set of seals, two per vane, which provides
sealing between the vanes and rotor.
6. Relief valve, on some models.
RELIEF VALVE
J yx . PUMP
y^-v
AXIS OF
ROTOR
ROTATION
A HOUSING
ROTOR
PUMP
HOUSING
VANE PRESSURE
RELIEF VALVE
CENTRIFUGAL
FILTER
SEALS
CENTERLINE OF PUMP BORE
AND AXIS OF VANE ROTATION
Figure 4
The pump vanes are located 180° apart and are in
constant near-contact with the pump housing bore.
The vanes are driven by the rotor, and slide through
the slits in the rotor.
Figure 3
IR PUMPS
wo different types of pumps have been used with
r injection systems. A 3-vane pump was used
'imarily on 1966 and 1967 California cars. A
vane pump was used in the majority of 1968 and
)69 AIR applications.
3th types perform the same basic function, com-
The three phases of 2-vane pump operation are
shown in Fig. 5.
Left view. As the vane rotates past the inlet port, it
provides an increasing volume. This has the effect of
producing a vacuum, which draws air into the pump.
Center view. When the second vane has passed the
inlet port, the air that was drawn into the pump is
PIPE EXTENSION
CYLINDER HEAD)
CARBURETOR
MUFFLER
ENGINE
EXHAUST
VALVES
COMBUSTION PIPE ASSEMBLY
CHECK
VALVE
(THRU MANIFOLD OR
FRESH AIR
DIVERTER VALVE
(IN OPEN POSITION)
AIR PUMP
-------
trapped between the two vanes. As the vanes con-
tinue to rotate, the trapped air is forced into a
smaller volume and thus compressed.
Right view. When the first vane has passed the outlet
port, the compressed air is expelled out of the port
and into the remainder of the system. It should be
noted that each full revolution completes two cycles
of intake, compression, and exhaust.
Figure 5
The 2-vane pump is unserviceable, except for the
pressure relief valve on units so equipped and the
centrifugal filter. When the pump is defective in-
ternally, it should be replaced as a complete as-
sembly.
CENTRIFUGAL FILTER
The 2-vane pump uses a centrifugal filter to clean
the air as it enters the inlet port and prevents foreign
particles in the air from entering the pump (Fig. 6).
Air enters the pump by passing the vanes of the
centrifugal filter. Because the vanes are being
rotated at high rpm, and because of their special
contour, any foreign particles in the air trying to
enter the pump are hit by the rotating vanes and
bounced out and away from the pump.
AIR ENTERING PUMP
AT CENTRIFUGAL
FOREIGN PARTICLES
BEING BOUNCED OFF
THE VANES
Figure 6
PRESSURE RELIEF VALVE
Some pumps incorporate a pressure relief valve in
the outlet port cavity (Fig. 7). The purpose of this
valve is to relieve pressure in the pump when it
exceeds a predetermined value.
The valve body encloses a preloaded spring, a seat,
and a pressure setting plug. When air pressure in the
pump builds up to the predetermined value, it forces
the valve seat up against the spring force, opens the
orifice, and relieves the pressure by exhausting it
into the atmosphere. This usually occurs at speeds
over 45 mph.
PRESSURE RELIEF VALVE
INCORPORATED IN PUMP
PRELOAD
-------
3-VANE PUMP
Externally, the appearance of the 3-vane pump (Fig.
9) is similar to that of the 2-vane pump. Func-
tionally, the intake, compression, and exhaust cycle
is exactly the same, but in this case the cycle is
completed three times per revolution instead of
twice (Fig. 10).
diverter valve. The purpose is to momentarily ex-
haust the air pump's output by diverting it into the
atmosphere, so that it cannot reach the exhaust
valve area during the initial stages of engine overrun
or deceleration.
Closing of the carburetor throttle valve during de-
celeration causes a high manifold vacuum which
draws a rich mixture of fuel into the cylinders. This
rich mixture cannot be completely burned in the
power stroke, so much of it is released through the
exhaust valves. If air from the pump were allowed to
combine with this hot and volatile mixture, backfire
would occur. It is the function of the diverter valve
to prevent that backfire.
During normal operation, air pump output is simply
routed through the diverter valve into the remainder
of the system.
Figure 9-
However, during engine overrun, a strong vacuum
signal, taken from just below the carburetor throttle
plate, is sent to the diverter valve diaphragm. This
vacuum signal is strong enough at this point to over-
come the spring force opposing the diaphragm
action. Consequently, the diaphragm is pulled up
against the spring (Fig. 11).
COMBUSTION PIPE ASSEMBLY
Figure 11
Figure 10
The 3-vane pump is serviceable, and any internal
troubles can be corrected by following appropriate
overhaul procedures.
DIVERTER VALVE
The majority of AIR installations incorporate a
The spool valve of the diverter valve is connected
directly to the diaphragm, so it also moves up and
seats in the upper position. The action of the spool
valve shuts off the passage into the remainder of the
system, and simultaneously opens a path that ex-
hausts the air pump output through the muffler to
OUTLET TO
DIVERTER
VALVE
PUMP
HOUSING
PUMP
COVER
INTAKE
TUBE
OUTLET TO
PRESSURE
RELIEF VALVE
VANE
ROTOR
AXIS
THE VANES ROTATE ABOUT THE UPPER AXIS. THE ROTOR, WHICH IS BELT DRIVEN
ROTATES ABOUT THE LOWER AXIS. FRESH AIR IS TRAPPED BETWEEN THE VANES AND
TRANSFERRED INTO A SMALLER VOLUME. THUS THE TRAPPED AIR IS COMPRESSED
BEFORE IT IS EXHAUSTEO INTO ThE SYSTEM.
STATIONARY
HOUSING
BELT DRIVEN
ROTOR
VANE
VANE
VANE
AXIS
AIR BEING
TRANSFERRED
INTO SMALLER
AREA
a:? BEING
DRAWN INTO
PUMP
COMPRESSED
AIR GOING
INTO SYSTEM
-------
VALVE PLATE
INLET
VALVE DISC
SPRING (hidden)
OUTLET
BODY
BACK-UP PLATE
CHECK VALVE ASSEMBLY
Figure 12
CHECK VAIVE
AIR MANIFOLD
ASSEMBLY
AIR MANIFOLD
ASSEMBLY
the atmosphere. This condition exists only momen-
tarily. A calibrated bleed hole in the diaphragm as-
sembly allows pressure to equalize on both sides of
the diaphragm, this allows the spool valve to revert
to its normal position after a very brief interval of
time.
Diverter valves are calibrated to function in ac-
cordance with the needs of each engine installation.
For this reason, they are not interchangeable.
NOTE: Some of the 1966 and 1967 California
cars used an "intake air bleed valve." This valve
functioned in a manner similar to that of the
diverter valve, except that during deceleration,
pump output air was routed to the intake mani-
fold rather than exhausted to the atmosphere.
I t has been mentioned that some diverter valves in-
corporate a pressure relief valve within them (Fig.
8). In this combined valve assembly, the diverter
valve action remains the same as just described, and
the action of the pressure relief valve is the same as
when it is incorporated in the pump assembly.
In some instances where replacement pumps have
been used, there might be a pressure relief valve in
both the pump and the diverter valve assembly. With
these installations, the relief valve in the pump has a
pressure setting plug which functionally blocks it
out of operation.
CHECK VALVE AND COMBUSTION PIPE
ASSEMBLY
The check valve in the AIR system is a one-way
valve that permits air flow in the direction of the
exhaust valves, but prevents flow in the direction of
the air pump (Fig. 12). This keeps exhaust gases
from entering and damaging the pump. One check
valve is used with 4, 6, and some 8-cylinder engines.
Other 8-cylinder engines use two check valves, one
for each combustion pipe assembly.
The air manifold or combustion pipe assembly
routes the air pump output to individual injection
tubes. These tubes are inserted into the cylinder
head or exhaust manifold, and direct air to the area
of the exhaust valves, where the exhaust gases are
dispelled from the cylinders. Fig. 13 shows typical
In Line and V-8 air manifold and injection tubes.
Figure 13
SYSTEM VARIATIONS
To avoid confusion, it should be noted that a
though some GM truck engines use the AIR systen
they also use a modified warm air system in coi
junction with the air cleaner (Fig. 14). However, tl
thermostatic control system is not used.
Warm air is furnished to the carburetor at all time
with no provisions to regulate the supply. The he;
stove used is less than fully efficient, and does nc
require precise regulation.
NOTE: Other Manufacturers may use air injet
tion systems together with a temperatun
controlled hot air cleaner, as explained in Manu;
No. I.
-------
NOTE: HEAT STOVE ON
Figure 14
SERVICING THE AIR SYSTEM
Oniy a properly tuned engine can provide full power
and performance, and full value from the AIR
system for the control of exhaust emissions.
Here is the basic recommendation for vehicles equip-
ped with the AIR system . . .
A check of system operation should be made at 4
months or 6,000 miles, whichever occurs first,
and at each tune-up interval, every 12 months or
12,000 miles. The initial check and each tune-up
should include adjustment of carburetor idle
speed, idle mixture, and engine timing.
The initial check at 4 months or 6,000 miles is desir-
able. After this break-in period, the engine operation
is more stabilized, and tune up settings will be less
subject to change.
CHECKING THE AIR SYSTEM
Checking the AIR system is relatively easy and re-
quires little time. Following is a list of the com-
ponents that should be checked and information on
how to check them.
DRIVE BELT
1. Inspect belt for wear, cracks, or deterioration.
Replace if necessary.
2. Check belt tension (Fig. 15), using strain ten-
sion gauge, and adjust if necessary. Belt set-
tings will vary slightly with different ap-
plications. A typical setting for a used belt is
55 lbs., and for a new belt 75 lbs.
Figure 15
AIR INJECTOR PUMP
Remove one of the outlet hoses. Accelerate the en-
gine to approximately 1500 rpm and observe the air
flow. If air Flow increases as the engine is ac-
celerated, the pump is operating satisfactorily. If the
air flow does not increase or is not present, proceed
as follows:
1. Check for proper drive belt tension.
2. Check for a leaky pressure relief valve (on
pumps so equipped). Air may be heard leaking
out of the valve with the pump running.
NOTE: The AIR system is not completely noise-
less. Under normal conditions, noise rises slightly
in pitch as engine speed increases. To determine
if excessive noise is the fault of the AIR system,
operate the engine with the pump drive belt re-
moved.
Before replacing a pump for excessive noise, make
sure that it has been operated in excess of the 100
mile break-in period. Also check all hose con-
nections and combustion pipe assemblies, as well as
proper mounting for the pump.
CAUTION: Do not introduce oil (Fig. 4) into the
pump through the front bearing vent hole. This
may quiet down the pump for a little while, but
will not fix it permanently and will eventually
lead to early pump failure.
DIVERTER VAI"'E
1. Check the condition and routing of all lines,
especially the vacuum signal line. All lines
must be secure, without crimps, and not leak-
ing.
-------
AIR MANIFOLDS AND HOSES
1. Inspect all hoses for deterioration or holes.
2. Inspect air manifolds for cracks or holes.
3. Check all hose and manifold connections.
4. Check all hose routings. Interference ma>
cause wear.
5. If a leak is suspected on the pressure side ol
the system, check the involved component oi
connection with a soapy water solution. Witl
the pump running, bubbles will form if a leal*
exists (Fig. 18). Be careful to keep the soap)
water solution away from the centrifugal filtei
of a 2-vane pump.
CAUTION: AIR hoses are made of special higl
temperature material. If a hose must be replaced
use only the proper type hose for the purpose
Do not use a substitute.
Figure 18
2. Disconnect the signal line at the valve. A vacu-
um signal must be available with the ermine
running (Fig. 16).
3. Reconnect the vacuum hose. With the engine
stabilized at idle, no air should be escaping
through the muffler. Manually open and
quickly close the throttle. A momentary blast
of air should discharge through the muffler for
at least one second (Fig. 17).
4. Defective valves should be replaced. They are
not serviceable internally.
CAUTION: Although sometimes similar ir. ap-
pearance, diverter valves are designed to meet the
particular requirements of various engines. There-
fore, be sure to look it up first, and then Jistall
the correct valve.
Figure 16
Figure 17
CHECK VALVE
1. The check valve should be inspected wheneve
the hose is disconnected from the check valve
or whenever check valve failure is suspectec
An inoperative pump that shows signs o
having had exhaust gases in the pump ir
dicates a check valve failure.
2. Orally blow through the check valve towar
the air manifold, then attempt to suck bac
through the check valve. Flow should be i
one direction only-toward the air manifol
(Fig. 19).
-------
AIR INJECTOR TUBES
1. There is no periodic service or inspection for
the air injector tubes. However, whenever the
cylinder heads or exhaust manifolds are re-
moved from an engine, inspect the air injector
tubes for carbon build-up and warped or burnt
tubes.
2. Remove any carbon build-up with a wire
brush.
3. Warped or burnt tubes must be replaced.
AIR SYSTEM DIAGNOSIS
The AIR system will limit exhaust emission to a
level below requirements if it is properly installed
and maintained. But will not provide the desired
reduction in exhaust emissions if some of the engine
components malfunction.
because of the relationship between Engine Tune
Up and Unburned Exhaust Gases, the condition of
the engine should be checked whenever the AIR
system seems to be malfunctioning. Particular care
should be taken in checking items that affect the
fuel-air ratio, such as the crankcase ventilation
system, the carburetor, and the carubretor air
cleaner.
If all other components seem to be operating
Figure 19
satisfactorily, visually inspect the AIR system as
previously explained.
If malfunction persists after completion of tune-up
and visual inspection, refer to the following
diagnosis chart for symptoms, probable cause, and
remedy.
TROUBLE
PROBABLE CAUSE
REMEDY
A. PUMP NOISY
Before trying to isolate the cause, it should be noted that the AIR system is not
completely noiseless. Under normal conditions, noise rises in amplitude as
engine speed increases. Air pump noise can be confused with other engine
noises.
Hose disconnected or leaking.
Re-connect or replace.
Overly torqued pivot bolt.
Torque to 15-20 ft. lbs.
Faulty relief valve (if mounted in
pump).
Replace valve.
A "chirping" noise may be prev-
alent on new pump.
Allow break-in time.
A continuous "knocking" noise is
indicative of rear breaking failure.
Replace pump.
Improper belt tension.
Readjust.
Seized or binding pump.
Replace.
Incorrect or missing pressure setting
plug (if relief valve is mounted on
pump).
Replace plug.
Bent or misaligned pulleys.
Inspect belt alignment,replace pulleys.
AIR SHOULD FLOW
IN THIS DIRECTION
ONLY
-------
TROUBLE (Cont'd.)
PROBABLE CAUSE (Cont'd.)
REMEDY (Cont'd.)
B. POPPING IN
EXHAUST SYSTEM:
HOT IDLE
COLD IDLE
(CHOKE ON)
ACCELERATION
Sound similar to muffler hitting floor
pan. Caused by rich idle mixture.
Same as above. Moderate popping is
inherent design characteristic of
system when cold.
Popping appears under load from
idle. Popping noise level varies with
timing (decreases with advance of
timing) and carb. accelerator pump
shot duration.
Adjust idle mixture screws, as shown
in United Delco 60A100-1 Specifica-
tion Manual.
Same as above. Also inspect choke and
vacuum break operation and settings.
On manual choke models, instruct
owner on proper operation.
Check ignition spark timing.* Check
accelerator pump adjustment.
C. BACKFIRE IN
EXHAUST SYSTEM
Rich fuel mixture caused by:
Inoperative choke, misadjusted or
sticking closed.
Inoperative vacuum break.
Use of manual choke:
Generally over-choking.
Air cleaner element restricted.
Improper crankcase vent
maintenance.
High fuel level.
Diverter valve stuck in open
position.
Diverter valve and distributor
timing vacuum lines switched.
Inspect choke operation, correct as
necessary.
Replace vacuum break.
Closer control of choking period.
Replace element.
Inspect system. Replace PCV valve.
Check fitting at carburetor; may be
plugged with crankcase deposits.
Check PCV filter. Replace if dirty.
Adjust float level.
Check valve. Replace if defective.
Correct hose routing.
D. BACKFIRE OR
POPPING IN
INLET MANIFOLD
Leaking inlet manifold.
Incorrect ignition timing.
Check manifold bolts for tightness.
Check timing and set to specs.*
E. OFF IDLE
HESITATION AND
ROUGH IDLE (HOT)
Appears in acceleration period from a
standing start to approximately 900
rpm and result from the following:
Vacuum leak - more noticeable on
hot engine. This results from uncon-
nected, split, or oversized hoses, or
from hot idle compensator not
closing, or opening prematurely. Can
also be caused by a leaking carburetor
or intake manifold gasket.
Inspect hoses, gaskets, and fittings for
leaks. Close carburetor hot idle com-
pensator. If this corrects condition,
replace hot idle compensator.
-------
TROUBLE (Cont'd.)
PROBABLE CAUSE (Cont'd.)
REMEDY (Cont'd.)
E. OFF IDLE
HESITATION AND
ROUGH IDLE (HOT)
(CONT'D.)
A third cause can be insufficient fuel
shot from carb. accelerator pump, or
fuel leaking past seal during pump
travel. (This does not apply to
diaphragm type accelerator pumps).
Carburetor float level low.
Initial timing out of specification.
Check accelerator pump adjustment.
If rubber seal is hard, or falls into
cavity by its own weight (with return
spring removed), it should be replaced.
There should be slight interference
between cup and wall.
Adjust as required.
Check initial setting to specification.*
F. ROUGH IDLE OR
SURGE
Improper carburetor adjustment,
idle speed, idle fuel mixture, choke,
etc.
Improper ignition timing.
Vacuum leak at signal line to
diverter valve or distributor,
vacuum leak at carburetor or
intake manifold.
Check carburetion and adjust as
necessary.*
Set timing to specs.*
Inspect and correct lines and con-
nections. Check for leaks at carburetor
and intake manifold gaskets.
G. ENGINE IDLE
SPEED HIGH
Throttle linkage sticking or
obstructed by hoses.
Idle speed set incorrectly.
Inspect linkage and eliminate points of
interference.
Reset idle speed to specs.*
H. ENGINE
"DIESELS" AFTER
IGNITION IS
TURNED OFF
Idle speed too high.
Solenoid (on units so equipped)
stuck in "up" position.
Low octane fuel.
Reset idle to specs.*
Free-up or replace solenoid.
Use higher octane fuel or premium.
I. OVERHEATED
EXHAUST
SYSTEM
Ignition timing retarded, excessive
burning in exhaust system.
Incorrect or missing pressure relief
valve plug in air pump.
Reset timing to specs.*
Check for correct plug. Install if
missing.
J. CHARRED,
DETERIORATED
SUPPLY HOSE
Defective check valves.
Replace check valves.
K. CONSTANT
AIR NOISE
Broken hose.
Diverter valve stuck closed.
Replace hose.
Replace diverter valve.
* Refer to United Delco 60A100-1 Specification Manual
CAUTION: Because the AIR pump air filter provides a
direct path into the pump, cover the filter whenever
cleaning the engine.
-------
CHRYSLER CAP SYSTEM
The Chrysler method for control of both crankcase
and exhaust emissions is called the Cleaner Air Pack-
age (CAP). It is sometimes referred to as the Cleaner
Air System (CAP) (Fig. 20).
haust emissions. Aside from standard tune-up pro
cedures, special consideration should be given t<
vacuum control valve checks where applicable am
carburetor adjustments.
In the CAP system, crankcase emissions are con-
trolled by a positive, fully closed crankcase ventila-
tion system that is similar to the typical system de-
scribed in Manual No. I.
For exhaust emission control, the CAP system uses
modified carburetion and ignition timing, plus some
basic engine design refinements.
VACUUM CONTROL VALVE OPERATION
The vacuum control valve is connected by vacuun
hoses to the distributor advance unit, the carbureto
vacuum port, and the intake manifold (Fig. 21).
VIHK1E f AITS AffKTED IY CHIYSIEI COIPOIATION ouumctoi t.Ur.
CUAKII Ail SYSTEM I •»« ¦IXTU"
IMMOVID MANIFOLD HCAr VAIVI • CHOKI
CIANKCASI VINTlUTCa VAIVI \ j • DASHPOT
- _ AUEtlO DlST«i»UTOt \ \ , SENSING VAIVI
Figure 20
The specially calibrated CAP carburetor delivers a
leaner idle mixture than non-CAP cars. There are no
significant changes in the calibration of the other
carburetor circuits.
The basic timing of CAP engines has been altered to
provide retarded ignition at idle speed. Although the
CAP distributor is essentially the same as a conven-
tional distributor, the mechanical and vacuum ad-
vance curves are specially calibrated for CAP igni-
tion requirements.
In addition, on some models, a vacuum control valve
is used to provide maximum vacuum advance during
deceleration.
Primarily, CAP equipped cars require periodic and
precise tune-up to maintain desired control of ex-
The chamber on one side of the valve is connectei
to both the carburetor vacuum port and the distri
butor vacuum advance unit. The chamber on th
other side of the vacuum valve is connected to thi
intake manifold. A spring holds the valve in a close<
position. However, strong manifold vacuum, actin;
on the valve's diaphragm, can overcome the sprinj
force and open the valve.
At engine idle speed, the vacuum control valve doe
not affect timing because intake manifold vacuum i
not strong enough to open the valve. The onl;
vacuum force acting on the distributor advance uni
is supplied by the carburetor port. At idle, vacuun
from the carburetor port is not strong enough t<
move the distributor diaphragm and advance th
ignition timing (Fig. 22).
iimitac
¦V ? - s*
-------
Figure 22
During acceleration and at cruising speeds, the car-
buretor throttle is open and manifold vacuum is not
strong enough to open the vacuum control valve.
That means that only vacuum from the carburetor
port is applied to the distributor vacuum advance
unit.
Since carburetor port vacuum is relatively high dur-
ing acceleration and at cruising speeds, normal igni-
tion advance is provided, just as it is in a conven-
tional ignition system.
During deceleration, the throttle is closed. Since car-
buretor vacuum port is above the throttle valve,
vacuum from this source is not strong enough to
provide vacuum advance at the distributor. How-
ever, manifold vacuum is now at or near maximum,
so it opens the vacuum valve (Fig. 23).
Figure 23
When the vacuum control valve opens, intake mani-
fold vacuum acts on the distributor vacuum advance
unit. This provides maximum vacuum advance dur-
ing deceleration (Fig. 24).
Figure 24
Because the ignition timing is greatly advanced on
CAP cars during deceleration, combustion starts
much earlier, allowing more time for complete com-
bustion. As a result, exhaust emissions are reduced
to an acceptable level.
IDLE SPEED AND MIXTURE ADJUSTMENTS
It is normal procedure to adjust idle mixture and
speed before testing or adjusting the vacuum control
valve. To eliminate the possibility of the timing
being advanced due to a leaking or incorrectly ad-
justed vacuum control valve either remove and plug
the manifold vacuum hose at the control valve end,
or use a spring clamp to pinch it shut. When a clamp
is used, make sure it does close off the hose com-
pletely and without damaging the hose (Fig. 25).
Figure 25
For adjusting idle speed and mixture both a tacho-
meter and combustion analyzer are used. When ad-
justing idle mixture, remember that a combustion
-------
analyzer is a very sensitive instrument. It takes
about ten seconds for the meter to stabilize after
each mixture adjustment. For best results, turn he
mixture adjustment no more than about 1/16 of a
turn between readings.
Final idle mixture adjustment must be made by ad-
justing from rich to lean not from lean to rich (Fig.
26).
If the mixture is too lean, the idle will be very
rough, and it will be difficult to keep the engine
running at specified engine speed. It is very im-
portant to maintain specified idle speed when ad-
justing idle mixture.
Watch the tachometer as well as the combustion
meter. If idle speed changes appreciably when ad-
justing mixture, readjust idle speed before pro-
ceeding with mixture adjustment.
In the case of multiple-barrel carburetors with two
mixture screws, a final independent adjustment of
the mixture screws may be made to improve idle
smoothness. Make sure this final adjustment doesn't
put the air-fuel ratio outside of CAP specifications.
If the air cleaner was removed when the idle mixture
screws were adjusted be sure to recheck meter read-
ings after air cleaner has been reinstalled.
CARBURETOR VACUUM CHECK
Before testing or adjusting the vacuum control valve,
make sure that vacuum at the carburetor vacuum
port above the throttle blade is correct.
To check, warm engine up to the normal operating
temperature. Connect a tachometer to the engine.
Connect a vacuum gauge into the distributor vacu-
um line. Use a tee fitting with the same inside dia-
meter as the line.
If the carburetor is equipped with a dash pot, adjust
it so that it does not contact the throttle lever at
idle speed.
Disconnect and plug hose that connects the vacuum
control valve to the intake manifold. Remove the
distributor vacuum hose at the distributor and plug
hose. The distributor vacuum must be zero (0) to six
(6) inches of mercury with the engine running at
idle. If vacuum is higher than six (6) inches of
mercury, recheck idle speed, timing, and air/fuel
ratio.
Figure 27
VACUUM CONTROL VALVE TESTS
One test hook-up is used to test both the operation
and the calibration of the vacuum control valve. The
vacuum gauge is connected into the distributor hose.
The distributor and manifold vacuum hoses are con-
nected normally and are not clamped shut (Fig. 28).
Figure 28
Remember that during deceleration, high manifold
vacuum should open the vacuum control valve. To
-------
check, simply speed the engine up to about 2000
rpm and hold for 5 seconds. Then release the
throttle and let the engine return to idle speed. If
the distributor vacuum increases to about 15 inches
of mercury the valve is opening as it should.
If the vacuum gauge holds this high reading for at
least one. but not more than three seconds, the valve
is operating properly. If vacuum drops immediately,
the valve is closing faster than it should (Fig. 29).
Figure 29
The vacuum should drop below six inches of
mercury in not more than three seconds (Fig. 30). If
vacuum drops below six in less than one second-or
takes more than three seconds to drop below 6-the
valve must be adjusted.
The adjustment of the spring in the vacuum control
valve determines how long the valve will be held
open by manifold vacuum.
Figure 30
VACUUM CONTROL VALVE ADJUSTMENT
The vacuum control valve adjusting screw is at the
spring end of the valve. Remove the valve cover to
adjust.
To Increase Time Valve Is Open: Turn the valve
adjusting screw counterclockwise. This reduces the
effective closing pressure of the spring, and lets the
valve stay open longer.
To Decrease Time Valve Is Open: Turn the valve
adjusting screw clockwise.
One Turn Equals 1/2-Inch: One turn of the adjust-
ing screw will change the valve setting ap-
proximately 1/2-inch of mercury. For example, if at
the end of three seconds the vacuum reading has
only dropped back to seven inches, two clockwise
turns of the screw should drop the reading to about
six inches in three seconds.
Be sure to retest the valve closing time after ad-
justing it. If the valve cannot be adjusted to specifi-
cations, it must be replaced.
-------
Nome-
Address.
PROCEDURE CHECK SHEET
Make of Vehicle
Model:
_Year_
Telephone No_
4 cyl. CI 6 cyl. O 8 cyl. C]
Mileage since last tune-up.
Mileage since last carburetor overhaul.
Customer Performance Complaints:
Poor Acceleration.
Engine Knocks or Pings.
Hard Starting Hot.
Preventive maintenance tune-up desired
(No specific performance complaints)
VI. IGNITION CIRCUIT TESTS AND ADJUSTMENTS
1. Electrical check for high resistance, grounds, shorts, etc.
Unsatisfactory C Satisfactory O
2. Adjust cam dwell—Specification O
3. Adjust timing—Specification Q
VII. FUEL, MANIFOLD AND EXHAUST EMISSION SYSTEM
SERVICE
1. Free heat riser valve with cleaner and lubricant.
2. Service P.C.V. and exhaust emission system.
3. Use carburetor and combustion chamber conditioner.
~
~
~
VIII. CARBURETOR AND FUEL SYSTEM SERVICE
1. Test fuel pump pressure.
~
2. Test fuel pump volume—approximately one pint in one
minute. Q
3. Simplified carburetor tune-up a* required. Q
4. Fuel filter service. O
5. Air cleaner service. d
6. Check choke linkage—unloader operation. d
7. Adjust idle mixture. D
8. Adjust idle speed. O
IX. CHARGING SYSTEM
1. Check charging voltage—Specification.
2. Charge battery as required.
~
~
X. GENERAL VEHICLE INSPECTION
Road Test.
~
MI-226
WE USE GENUINE UNITED DELCO PARTS
Figure 31
Printed in U.S.A.
-------
ENGINE TUNE-UP PROCEDURE
The first five steps in a complete engine tune-up procedure were explained in the Number 1 Manual. Following
is an explanation of the remaining five steps. You will note that each of these procedures relates to the
unscreened portion of the "Power Service" check sheet on the opposite page. Using this type of procedure
check sheet on every tune-up job will not only help you in recording necessary information but will assure the
completion of all checks and adjustments before a car is delivered to its owner.
VI. IGNITION CIRCUIT TESTS
AND ADJUSTMENTS
1A Voltage Checks
Two simple checks will indicate any
"ground" or poor connections and reveal
any "open" in the coil primary windings or
elsewhere in the primary ignition circuit.
(Fig. 32) Connect the positive lead of a volt-
meter (on negative ground systems) to the
primary terminal on the ignition switch side
of the coil and the negative lead to ground:
a. With the ignition switch on and the distri-
butor points open the meter should read
battery voltage.
b. With the ignition switch on and the distri-
butor points closed the meter should nor-
mally read 4.5 to 7.5 volts (12 volt
system). A 12 volt reading would indicate a
shorted or by-passed primary ignition resis-
tance.
POiNTS OPEN
POINTS CLOSED
IGNITION
SWITCH
rd\[\
r
i4
Figure 32
A test for distributor primary circuit and contact
point resistance should be made to assure that
points have been installed and connected properly.
(Fig. 33).
Connect the positive voltmeter lead either to the
distributor primary terminal or the primary terminal
on distributor side of the coil. Connect the negative
meter lead to ground. With the ignition switch on
and distributor points closed, the voltmeter should
read .2 volt maximum.
Figure 33
IB Ignition Wave Form Analysis
BASIC IGNITION WAVE FORM (Fig. 34)
Ignition wave form analysis with an oscillo-
scope is a good method of checking the com-
plete ignition system. It requires an under-
standing of basic ignition as well as a
knowledge of the particular oscilloscope being
used.
A characteristic wave form (Fig. 34) indicates
voltage variations during the points closed por-
tions of a complete ignition cycle. For analysis
purposes the pattern is divided into three well
defined sections that makes it possible, by
comparison, to isolate abnormal conditions to
specific related areas in the ignition circuit.
359
POINTS CLOSED
-------
c IGNITION WAV! FO«M ANALYSIS
con ANO
coMOcmH
mcdom
KXXTJ COM)
Figure 34
POINTS OPEN (Fig. 35)
As the points open, instantaneous collapse of
the coil magnetic field produces the high volt-
age required to fire the spark plug. (Fig. 35)
This is indicated by the vertical firing line.
Voltage then drops to the lower level required
to maintain the spark as indicated by the
spark line. The oscillations represent dis-
sipation of energy in the circuit after the
spark has ceased.
I
a a,
y
'
Figure 35
POINTS CLOSED (Fig. 36)
As the points close, all action in the secondary
circuit has ceased and current starts to flow in
the primary circuit. (Fig. 36) This action con-
tinues for the entire points closed (cam dwell)
period thus building up the coil magnetic field
in preparation for the next firing impulse. A
normal points closed signal is represented by a
slight voltage drop followed by diminishing
oscillations. Variations at this point, or at the
end of the points closed period, indicate poor
breaker point action.
POiNfS aOSI SIGNAL
r
FOUR CYLINDER PATTERN COMPAR1SO
(Fig. 37)
Analysis starts with the comparison of the pa
tern for any one cylinder against a recognize
normal pattern and is followed by a complej
comparison of the patterns for all cylinder
(Fig. 37) If variations from normal are notice
in all patterns, trouble exists in that portion c
the circuit affecting all cylinders. A variatio
in one pattern isolates trouble to the portid
of the circuit affecting that cylinder only.
ctl#,
\
i
CTL*.
1_
1
** | on. ji
1
1
1
— . .
r: r ..
- -+
—Iiy..
1-
!
i
1
1
Hi'- r
i
1
1
Figure 37
FIRING SECTION VARIATIONS (Fig. 38)
The next step in analysis is to examine varia
tions that might exist in each of the threi
basic wave form sections. For each variatioi
shown there is one most common source o
trouble. In the firing section:
High firing line with high short spark line ir
dicates wide spark plug gap.
Low firing line with low long spark line ind
cates narrow plug gap.
Normal firing line with sloping spark line indl
cates excessive series resistance in cables, plug
or suppressors.
Spark line sloping from top of firing line indi
cates leaded or fouled plugs.
1 I
i
1
i
i
1
1
|
1
1 .
n i ix
I *
Figure 36
Figure 38
FIRING AND COIL SECTION VARIATION
(Fig. 39)
1
Extremely high oscillations with no firing o
spark line indicates an open circuit conditio!
-------
or a pattern that can be obtained t*or test pur-
poses by removing a spark plug lead. The up-
ward extent of oscillations indicates available
voltage.
A false start at the spark line indicates con-
taminated points or high series resistance in
condenser.
Lack of normal oscillations indicates defective
coil.
Figure 39
DWELL SECTION VARIATIONS (Fig. 40)
- Excessive cam dwell is indicated when the
complete point closed portion of pattern is
longer than normal.
- Short dwell is indicated when points closed
period is less than normal.
- A points closed signal with the first oscillation
shorter than the second indicates poor point
alignment.
- Flashing or lack of a clean break at end of
pattern indicates arcing contact points.
2. Adjust cam dwell (angle) (Fig. 41) with a
meter using exact specifications as found in
the United Delco 60A-100-1 Specification
Manual. This is preferable to adjusting contact
point opening with a feeler gauge, since it
eliminates the possibility of getting oil or dirt
on contact surfaces. On internal adjustment
type distributors, the adjustment can be per-
formed at cranking speed and double checked
with the engine running. On external adjust-
ment distributors, the adjustment can be made
with the engine running as shown in Fig. 41.
Prior to adjusting cam dwell, be sure to cali-
brate meter and place the cylinder selector
switch in the correct position. Then connect
1. 0
2. 0
3. o
4. o
i
W*—
—
"
|
Figure 40
\ /
POMT* OMMB) P04MTS CLOUD
Figure 41
positive meter lead (on negative ground
systems) to distributor primary terminal or
distributor side of coil and negative lead to
good engine ground position. Dwell adjust-
ment should be made at idle speed.
3. The final step in servicing the ignition system
is to adjust initial spark timing. Refer to the
60A-100-1 United Delco Specification Manual
for the following information on the specific
engine involved:
a. Location of No. 1 cylinder
b. Timing mark location
c. Timing Specification
Connect timing light according to equipment
manufacturer instructions. The engine should
be at idle speed or at the speed specified for
timing in the specification manual and the
vacuum line should be disconnected from the
distributor and plugged.
-------
Timing adjustment is accomplished by loosen-
ing the distributor hold down screws and
rotating the distributor until the timing muTks
line up according to exact timing specifi-
cations. This is one of the most critical adjust-
ments required for emission control. Be sure
to set to specification.
c. Check complete PCV system with tester
(Fig. 44)
d. Check and/or adjust pump drive belt ten-
sion on air injector equipped cars.
e. Visually check temperature controlled hot
air cleaner operation on vehicles so equip-
ped.
"Jt.'ifr-
Mlp
mm*
TESTER
WINDOW
IP.C.V. SYSTEM
FRESH AIR
INLET PLUGGED
Figure 42
VII MANIFOLD AND EMISSION SYSTEM
SERVICE
1. Servicing the heat riser (manifold heat con-
trol) valve (Fig. 43) is one of the most over-
looked operations in tune-up. Valve should
move freely and return to closed position by
the action of the spring. Tap valve shaft
lightly, if necessary, and check for free spring
weight action. When valve is operating freely
apply special cleaner - lubricant to both ends
of valve shaft. Do not use oil.
Figure 43
2. Servicing the PCV and exhaust emission
systems during tune-yp consists of the follow-
ing:
a. Replace PCV Valve
b. Replace or clean PCV system Filter
Figure 45
3. Use of a carburetor and combustion chamber
conditioner is recommended during each
tune-up (Fig. 45). This solvent will clean out
carbon and gum deposits around the choke
valve and in the carburetor bore. It will also
remove these deposits from the intake mani-
fold and combustion chambers. In most in-
stances, uneven or abnormal compression will
be corrected.
Figure 44
COUNTER-
THERMOSTATIC
SPRING
HEAT RISER
VALVE
-------
VIII CARBURETOR AND FUEL SYSTEM
SERVICE
1-5 A complete tune-up procedure should in-
clude a check of fuel pump pressure and
volume (Fig. 46). Where required minor
service should be performed on the carbure-
tor. This should include float level adjust-
ment as well as replacement of the pump
plunger, needle and seat and bowl cover
gasket. For high mileage cars, a complete
carburetor overhaul or unit replacement
should be considered.
On every tune-up, the fuel strainer (filter) and
carburetor air filter should be checked and
cleaned or replaced as required.
Figure 46
6. Any air leaks into the manifold or carburetor
can be detrimental to engine performance.
Always check the tightness of both manifold
and carburetor hold down nuts (Fig. 47). Also
tighten all carburetor cover screws.
Many types of vacuum hoses will be found on
emission controlled engines. They should be
checked for disconnections or leaks as well as
for proper re-connection if they have been re-
moved for any reason.
Check all carburetor linkage for binding or ex-
cessive looseness. With the accelerator pedal
depressed to floor board, observe the carbure-
tor throttle valve to determine that it goes to
the wide open position. At this point observe
the choke valve to insure that it is in a partial
open or unloading position.
7. Adjustment of carburetor idle mixture (Fig.
48) is a most important procedure particularly
on emission controlled engines. With most
engines, this adjustment is performed with a
tachometer. However, with Chrysler emission
controlled engines an exhaust gas analyzer is
also recommended.
For specific procedure applicable to each en-
gine application refer to the United Delco
60A-100-1 Specification Manual. Follow these
procedures closely to obtain proper engine
performance as well as control of exhaust
emissions.
Idle mixture adjustments should be made at
normal engine operating temperatures. To in-
sure accuracy make sure that idle compensator
is closed on carburetors so equipped.
8. Carburetor idle speed is also a particularly im-
portant adjustment on emission controlled en-
gines. Basically these engines require a higher
idle speed setting but it should not be ex-
ceeded. The most basic requirement is an ac-
curate tachometer - make sure your tacho-
meter is checked and calibrated periodically.
Adjust idle speed after referring to Specifi-
cation Manual for exact speed setting and
position of shift lever, drive or neutral, in
-------
Figure 43
Figure 49
which adjustment should be made. On car-
buretor with two throttle stop screws (Fig.
49) be sure to use only the one for slow idle
adjustment.
Since idle speed and mixture adjustments are
inter-related, it might be necessary to repeat
both adjustments to obtain best idle perfor-
mance at specified idle speed.
Engines equipped with a throttle stop solenoid
require two idle speed adjustments. Curb-idle
is obtained by adjusting the solenoid stop
screw with the solenoid energized. Slow idle
(stop) speed is obtained by adjusting the car-
buretor throttle stop screw with the solenoid
de-energized (disconnected).
IX CHARGING SYSTEM
1. Check charging voltage with a voltmeter con-
nected across the battery posts (Fig. 50). If
voltage is within specified range, it indicates
that all units of the charging circuit are func-
tioning properly and that battery should main-
tain a full charge condition.
IGNITION SWITCH
Figure 50
2. A final recommendation - never deliver a
tuned up car with the battery in a low state of
charge. Even though there is no charging cir-
cuit trouble, the battery might have become
discharged due to abnormal operation. Charge
the battery and make your tune-up complete.
X GENERAL VEHICLE INSPECTION
Final safety checks during tune-up should in-
clude inspection of lights, windshield wipers,
horns, brakes, and exhaust system.
Customer satisfaction with tune-up is assured
through a final road test that checks vehicle
performance under normal operating condi-
tions. Check for ease of starting, acceleration,
performance in the 30 to 35 MPH and 50 to
60 MPH ranges, stall at sudden stop and
roughness at hot idle.
Figure 51
-------
TABLE OF CONTENTS
Introduction 365
Current Approaches to Emission Control -366
Exhaust Gas Recirculation (EGR) 367
General Motors
Combustion Control Devices (1968) 367
Thermostatic Vacuum Switch 367
Anti-Dieseiing Solenoid 367
Combustion Control Devices(1970) 368
Transmission Controlled Spark 368
TCS Solenoid 368
Combustion Control Devices(1971) ogo
TVS-TCS Combination Switch 368
Combined Emission Control (CEC) ^q
CEC Solenoid 3gg
Combustion Control Devices(1972) 369
Speed Control Spark (SCS) 369
CEC System 369
TCS & SCS Systems 370
EGR (1972-73) 371
General Motors Combustion Control
Equipment Charts 372
Ford Motor Company
Combustion Control Devices(1968) 375
Dual-Diaphragm Distributor 375
Distributor Vacuum Control Valve 375
Combustion Control Devices (1970) 37 6
Distributor Modulator System 376
Combustion Control Devices(1971) 376
Pinto Decel Valve
Ford Motor Company (cont'd.)
Combustion Control Device (1972) -376
Electronic Spark Control (ESC) 376
Transmission Regulated Spark (TRS) System .... 3 77
Ford Motor Combustion Control
Equipment Summary .377
Chrysler Corporation
Combustion Control Devices (1968) 377
Vacuum Control Valve 377
Combustion Control Devices(1970) 378
Distributor Solenoid (Modulator) .3 7 g
Combustion Control Devices(1971-72) 378
Chrysler NOx System .378
Transmission Controlled Spark System 37 8
Speed Controlled Spark System .3 7 g
Distributor Solenoid (Advance for Start) 379
Exhaust Gas Recirculation (EGR) 379
Chrysler Corporation Combustion Control
Equipment Summary 379
.American Motors
Combustion Control Devices (1970-72) 380
Deceleration Valve 380
Transmission-And Speed-Controlled Spark Systems 380
Coolant Temperature Override Switch 380
American Motors Combustion Control
Equipment Summary 381
Evaporative Emission Control Systems
(All Makes 1970-72) 381
EEC Chart (All Makes) 385
INTRODUCTION
This Emission Control Service Part III Manual, is an extension of the information contained in Manuals No. 1 and No. 11. These
are available through your United Delco wholesaler. Essentially, this new manual covers the emission control systems used on
1968 through 1973 domestic vehicles.
The task of controlling automotive emissions requires the industry to conduct continuous and extensive research and development
programs. Changes in systems are made as research indicates their effectiveness. Information in this and the previous two Emission
Control Manuals is obtained from reliable sources but should not be considered absolutely accurate, complete or final.
In Emission Control Service Part No. I, you were introduced to the closed-type Positive Crankcase Ventilation System (PCV),
which is used on all '68 and later vehicles, and the Controlled Combustion System (CCS) with the Thermostatically-Controlled
Air Cleaner, stiil used on most '68 through '73 cars. Since the current versions of these devices are essentially the same as those
described in Manual 1, no further explanation of their operation will be covered in this Manual.
In Emission Control Service Part No. II, you were introduced to the Air Injector Reactor System (AIR), that helps complete the
burning of any fuel leaving the combustion chamber, by injecting air into the exhaust manifold. Again, since the AIR devices used
on '68 through '73 cars are essentially the same as those described in Manual II, no further explanation of AIR will be covered in
this Manual.
In addition. Manuals No. I and II introduced you to some new devices added to the carburetor-distributor system which (1)
controlled the position of the throttle stop (such as the idle stop solenoid) or (2) which modified the basic spark advance curve
(such as the dual-action vacuum advance-retard control). While some of these devices are still used as described, others have been
refined or combined into new systems. For this reason, the area of throttle stop and advance controls, as used on '68 through '73
cars, will be covered in detail.
This Manual will also cover two systems not previously described. These are the Evaporation Emission Control System (EEC),
-------
which prevents fuel vapors from the fuel tank and carburetor from being vented to the atmosphere, and the Exhaust Gas
Recirculation System (EGR), which recycles a metered amount of exhaust gas back through the induction system.
To test your understanding of the material presented, an examination is included with this Manual. You are already familiar with
these quizzes if you completed the previous two Manual examinations. From each of the three possible answers, select the one
that you believe to be correct. Mark down your choice in the proper box on the answer card and drop the post paid card in the
mail.
When you have successfully completed the examinations, you will receive a diploma which will assure your customers that you
have received United Delco Power Service training in Emission Control Systems.
CURRENT APPROACHES TO
EMISSION CONTROL
Before undertaking the detailed description of the various
emission control systems and devices used on '68 through '73
domestic vehicles, let's take a moment to review, in general
terms, the basic methods, currently used, to provide accept-
able levels of hydrocarbon and carbon monoxide emission.
The basic feature of all current automotive engines is a
specially-calibrated carburetor that mixes a larger amount of
air with a given amount of gasoline. The resulting air-fuel
mixture is leaner than was previously normal. In addition to
the carburetor, all current engines use a Thermostatically-
Controlled Air Cleaner (TAC), that insures that, after the first
few minutes of engine operation, the air reaching the carbure-
tor is warm regardless of outside temperature. The warmed air
allows for leaner calibrations while retaining responsive engine
operation in cold weather.
It's important to recognize some vital facts about today's
leaner-mixture-burning engines:
1. The fact that a leaner mixture (less fuel per unit of air) is
used is, by itself, no guarantee that there will be fewer
exhaust emissions. The fact that today's leaner mixture en-
gines use more fuel to produce comparable performance is
proof that more fuel must be passing into the exhaust sys-
tem in un- or partially-burned form, before releasing useful
heat energy in the combustion chambers.
2. The fact is that leaner mixtures, even though they burn less
efficiently in the combustion chamber, do lend themselves
to an engine design that provides greatly improved fuel
burning in the exhaust manifold, with the result that fewer
unburned fuel emissions reach the atmosphere.
Consequently, some of the emission-control devices, currently
used, are for the purpose of providing more complete burning
of un- or partially-burned comBustibles in the exhaust mani-
fold. Let's take a closer look at how this works and why it is
necessary.
LEAN MIXTURE EMISSION CONTROL
In today's automotive engines, there is not sufficient time,
during the power and exhaust strokes, to allow all the fuel to
burn completely within the combustion chamber. Some
unburned fuel will escape into the exhaust, causing a potential
emission problem.
With a normal mixture and spark advance, burning occurs rela-
tively quickly and efficiently with most of the heat energy in
the fuel converted into useful power. As a result, the gases
exhausted into the exhaust manifold are relatively cool... so
cool that there is insufficient heat to complete the burning of
residual fuel in the exhaust system. This causes the high emis-
sion levels of normal engines.
With a lean mixture, burning is much slower, so when a normal
spark advance is used, more unburned fuel escapes into the
exhaust system. While the temperature of this gas is hotter
than that of a normal mixture, it is still not hot enough to
insure complete burning in the exhaust manifold.
Advancing the spark (to provide more burning time) does not
solve the problem since this results in even colder exhaust
temperatures as well as running the risk of damaging detona-
tion. Instead, in current practice, the spark is retarded. While
this results in a further drop in power efficiency, it does raise
the exhaust temperature sufficiently high to insure relatively
complete burning of any unburned fuel reaching the exhaust
manifold, resulting in acceptably-low emission levels leaving
the tail-pipe.
A comparatively-recent development, the Air Injection Reac-
tor (AIR), further enhances this process by injecting additional
air into the exhaust manifold to insure more complete burning
of fuel residues.
LEAN MIXTURE DRIVEABILITY CONTROL
The great bulk of driving is done under steady speed condi-
tions under which a regarded spark gives satisfactory drive-
ability. However, under certain short-duration situations, the
retarded spark can cause problems, such as hard starting, cold-
engine stalling, poor acceleration.
To minimize these effects, some of the emission devices used
on current engines are designed to improve driveability by
providing a temporary spark advance, during these transient
conditions. Some of these spark-advance devices may be ac-
tuated by low or very-high engine temperatures, low-gear or
low-speed operation, time, or by low manifold vacuum. Al-
though it's true that while these devices are operating emis-
sions are increased, the total amount of such operations during
a typical drive are sufficiently brief so that the total amount of
emissions produced are held within acceptable limits.
In the following discussion, we will cover just what type of
lean-mixture emission and driveability controls are used on
which cars, as well as how they operate.
-------
EXHAUST GAS RECIRCULATION (EGR)
Most 1973 Models
The purpose of EGR is to reduce combustion temperatures, by
diluting the incoming air-fuel mixture with small amounts of
exhaust gases drawn from the exhaust manifold. The principle
is that since exhaust gases have already been burned they can't
be burned again, so their presence in the combustion chamber
adds a cooling effect, reducing peak combustion temperatures.
The prime purpose of the EGR is to reduce the formation of
oxides of nitrogen (NOx) which occur most readily at high
combustion temperatures.
engine temperature. Opening the throttle slightly produces
high vacuum at a port in the carburetor which is carried to the
TVS at port "C", bypassing the spring-loaded valve, so the
vacuum acts directly on the distributor spark vacuum advance
through port "D". This is termed 'Timed Spark". On
1968-1970 Air-conditioned Cadillacs, the TVS incorporates a
fourth port, designated "FIP" (Fast Idle Port). This port is
connected to a fast idle device, located on the carburetor,
which is actuated by manifold vacuum, when the TVS valve is
opened by high heat conditions.
VACUUM TO BE
CONNECTED TO
TIMED PORT IN
CARBURETOR
DIAPHRAGM
^ COVER
SPRING
VAI_VE>SHAFT-+-i
"V
SEA^^
VALVE
CHAMBER
TO INTAKE
MANIFOLD
f ACTUATING
DIAPHRAGM
VALVE OPEN
VALVE CLOSED
VALVE SEAT
EXHAUST GAS
PORT INLET
3UICK EGR CONTROL VALVE
GENERAL MOTORS COMBUSTION CONTROL
DEVICES ON 1S6S AND LATER CARS
Thermostatic Vacuum Switch (TVS)
The retarded spark advance, used to insure most satisfactory
combustion of lean mixtures, at low engine speeds, can cause
overheating in prolonged idle or low speed conditions. To pro-
tect against overheating, many General Motors engines are
equipped with a thermostatic vacuum switch (TVS); actually a
valve that is located in the engine cooling jacket to control the
vacuum spark advance system. While the TVS in later cars may
be part of other GM control systems (TCS, SCS, CEC), its
function is distinct.
One function of the TVS is to permit normal spark advance
when the engine coolant exceeds a specified temperature level
(235°F.). When this happens, the valve opens against spring
pressure and allows intake manifold vacuum (through port
"MT") to reach the distributor spark advance system (through
port "D") advancing the spark, resulting in a faster idle for
better fan cooling and less heat rejection iftto the cooling
system.
A second function is to provide spark advance whenever the
throttle is opened slightly above the idle position, at normal
TYPICAL GM TVS VALVE
Anti-Dieseling Solenoid
One characteristic of engines designed for emission control is
higher idle speed, often high enough to cause "dieseling" or
"running on" of the engine after the ignition switch is turned
off. To prevent this, a solenoid is incorporated into the idle
stop. When the ignition switch is "on", the solenoid plunger
moves out (energized) to provide a normal idle position. How-
ever, when the switch is turned "off', a spring returns the
solenoid plunger to a position that permits an almost complete
closing of the throttle plate, starving the engine to a stop.
HCSE
(THERMO YAC SWITCH
TODIST.) hOSE (THERMO
SWITCH TO TEE)
THERMO VAC
SWITCH
HOSE
(THERMO VAC SWITCH
TO CARS)
HOSE
(TEE TO CARd)
TYPICAL GM TVS HOSE ROUTING
PORT PORT
D "Kl PORT
f i _ MT
-------
Initially, the anti-dieseling solenoid was used only in engines
most prone to dieseling. However, as emission control devices
have become more effective and dieseling more common, the
Anti-Dieseling Solenoid is now used on all Buicks, Cadillacs
and Chevrolets, and most Oldsmobiles and Pontiacs.
iOif SPEED
ADJUSTMENT SCHEW
,*j«N 10 ADJUST'
USE TO ADJUST
ENGINE SHUTDOWN
«PM ONLY (SEE DECAl
TYPICAL ANTI-DIESELING SOLENOID
INSTALLATION
On some models oi Ueneral Motors cars, a temperature over-
ride switch, located in the engine block, is incorporated into
the circuit which deactivates the solenoid (permitting normal
advance) when the coolant is below or above certain tempera-
tures, to improve cold-engine operation or improve engine
cooling (see switch and relay circuit in illustration). On
Cadillacs, some Buicks and Olds engines, the overheat pro-
tection is provided by a separate TVS valve.
GENERAL MOTORS COMBUSTION CONTROL
DEVICES AND SYSTEMS ON 1971
AND LATER CARS
TVS-TCS Combination Switch
The TVS-TCS switch (sometimes called the distributor Vac-
uum Control Switch) was first used on some 1971 Olds en-
gines. Essentially, it combines the functions of the TCS sole-
noid and the TVS valves into one block-mounted unit. The
unit advances the spark whenever the transmission is in third
or fourth gear, or whenever coolant temperature reaches blow-
off temperatures (about 235°F.).
GENERAL MOTORS COMBUSTION CONTROL
DEVICES AND SYSTEMS ON 1970
AND LATER CARS
Transmission Controlled Spark (TCS)
The TCS system prevents normal spark advance when the car
is operating in the lower gears. In some cars, the system func-
tions only when the engine is at normal operating tempera-
tures. A greater throttle opening is required to achieve a given
level of acceleration, thus improving mixture distribution and
combustion emission efficiency. HC and CO emissions are re-
duced at low speeds.
1970 VERSION OF TCS SYSTEM
TCS Solenoid
The key element of the TCS system is a solenoid that, when
energized, cuts off manifold vacuum to the spark advance
system of the distributor. The solenoid is energized by a trans-
mission switch that is normally closed when the transmission is
in the lower gears.
The switch is oil pressure operated on automatic transmission
cars, mechanically operated on manual transmission cars.
When the transmission is in "drive" or final gear, the
transmission switch is open, de-energizing the solenoid and
allowing normal spark advance.
TVS-TCS COMBINATION SWITCH
As in the separate TVS valve, the source of vacuum for advanc-
ing the spark is from the intake manifold when temperature is
in excess of 235°F. or a port in the carburetor throat above the
throttle valves at normal engine temperatures.
Combined Emission Control (CEC)
The heart of the CEC system is a solenoid that provides two
functions: A transmission-controlled spark advance (like TCS).
and a two position throttle stop. The solenoid is controlled by
four electrical units: a temperature override switch, a time-
delay relay, and a transmission switch, working in conjunction
-------
with a reversing relay. Except Vega, the CEC system is used on
all 1971 Chevrolets and 1972 six-cylinder Chevrolets and Pon-
tiacs.
COMBINATION EMISSION CONTROL
(CEC) SYSTEM
CEC Solenoid
While the CEC solenoid is similar to other GM TCS solenoids
in that it permits spark advance only in final gears, it differs in
one important aspect: When in lower gears, the solenoid is
de-energized to cut off spark advance; in high gears the sole-
noid is energized to permit spark advance. This energize-de-
energize "pattern is just the opposite of that of other GM TCS
systems.
Another distinction is that the plunger of the solenoid extends
from the housing. When energized, the plunger is extended to
provide a fast idle throttle position to improve emission con-
trol during high gear deceleration. When the solenoid is de-
energized, the plunger retracts to allow the throttle lever to
return to curb idle position (adjustable by a separate Idle Stop
screw). Since the curb idle speed is relatively low, there is no
tendency to diesel when turning the ignition switch off.
Transmission Switch and Reversing Relay
Although the CEC transmission switch is normally closed in
lower gears (as in TCS systems), the switch energizes a revers-
ing relay (instead of the solenoid). When energized, the relay
opens the circuit to the solenoid and de-energizes it. Opening
the transmission switch (high gear) de-energizes the reversing
relay closing the circuit to the solenoid and energizing it.
Temperature Override Switch
The temperature switch includes a cold override feature which
provides vacuum advance whenever coolant temperatures are
below SOT. On some high-performance engines, a hot override
is also provided in the same switch.
Time-Delay Relay
The time-delay relay is energized from the ignition switch to
provide 20 seconds of vacuum advance to improve hot-engine
starting. When the engine is cold, the relay does not function,
since current is by-passed into the closed cold override switch
to ground.
CEC SOLENOID ON CARBURETOR
GENERAL MOTORS COMBUSTION CONTROL
DEVICES AND SYSTEMS ON 1972
AND LATER CARS
Speed Control Spark (SCS) System
Tne SCS system used on Cadillacs and some Pontiac models is
similar in function to the TCS system. However, in place of
the TCS's transmission switch, the SCS system uses a car speed
sensing switch, mounted in the transmission or in series with
the speedometer cable.
The SCS switch, controlled by centrifugal fly-weights, is
normally closed and keeps the solenoid energized to prevent
vacuum spark advance. When car speed reaches approximately
35 mph, the fly-weights spread, opening the switch, de-
energizing the solenoid and permitting vacuum advance. How-
ever, on deceleration, car speed must fail below 25 mph before
the switch closes, shutting off vacuum advance.
INTAKE MANIFOLD VACUUM
TYPICAL SPEED CONTROL (SCSI SYSTEM
Combined Emission Control (CEC) System
The CEC system used on 1972 Chevrolet and Pontiac Six en-
gines differs somewhat from the 1971 version of CEC. In '72,
the solenoid plunger, when energized in high gear (giving vac-
uum advance) still extends to provide a fast idle throttle stop
position. However, when the plunger is de-energized (low
-------
gear), the curb idle position is provided by a separate anti-
dieseiing solenoid (energized when the ignition switch is on -
plunger extended). When the anti-dieseling solenoid is de-
energized (ignition switch turned off - plunger retracted), a
more complete closing of the throttle plate insures positive
shut-down. Note, then, that the CEC system provides three
throttle '.top positions: Fast idle, curb idle, and shut-down.
Anoth n feature of the '72 CEC system is the elimination of
the rf versing relay. The CEC vacuum advance solenoid is ener-
gjze j by grounding a normally-open transmission switch (in
plr.ce of the '71 normally-closed switch which was used in
conjunction with the reversing relay). This insures retention of
a characteristic distinctive to Chevrolet systems: the solenoid
is energized to provide vacuum advance (not de-energized as in
other CM systems)
'.Ans»y
fO o-
iGN. switch
EHGINE
OVER* EAT LIGHT
DIST. VACUUM
ADVANCE
UNIT —<
- IDLE STOP SOlENQlD
TEMPERATURE
SWITCH
TRANSMISSION
SWITCH
20 SECOND
time relay
Olds
The Olds uses a TCS system. Temperature factors on all en-
gines (except 350 V-8 with manual transmission) are handled
by the TVS valve which is an integral part of the vacuum
advance solenoid (TCS-TVS Combination Switch). An anti-
dieseling solenoid is used on most engines.
TCS
SWITCH
TCS
SOLENOID
o
TO
¦~IGNITION
SWITCH
OLDS TCS CIRCUIT
(ENGINES WITHOUT ANTI-DIESELING
SOLENOID)
Pontiac V-8
All Pontiac V-8s (except those with 4-spoed or 307 C.I.D.
engine) use a SCS system. Those with 4-spved or 307 C.I.D.
engine use a TCS system. Temperature facto/s are handled by
a temperature hot/cold override switch, controlling the vac-
uum advance solenoid. In addition, 307 engines (TCS system)
incorporate a TCS delay relay which delays vacuum advance
when the car is shifted into high gear for a period of 20 sec-
onds. This requires a greater throttle opening to achieve a
given level of acceleration. Mixture distribution anc1 combus-
tion efficiency are improved thereby reducing HC and CO
emissions at low engine speed. An anti-dieseling so'.enoid is
used only on 307 and 4-barrel carburetor engines.
CEC ELECTRICAL DIAGRAM (1972)
TCS arid SCS Systems
All other 1972 General Motors cars use a TCS or SCS system
in which the vacuum advance solenoid is essentially the same
as in previous years: Energizing the solenoid prevents vacuum
advance (except Chevrolet V-8s). However, there are other
component and circuit differences.
Cadillac
Cadillac uses a SCS system with temperature factors handled
by a separate TVS v?Jve.
VACUUM
SCLENOIO
VALVE
Ln
TCS ORSPI
(SPEED
SWITCH
31"
CH
IDLE
STOP
.SOLENOID
FUSE BOX
¦¦
~)TO
IGNITIGN
SWITCH
CADILLAC SCS CIRCUIT
Buick
The Buick uses a. TCS system. Temperature factors on some
engines are handled by a separate TVS valve.
TCS
VACUUM
SOLENOID
~
TCS OR
SPEED SWITCH
IDLE STOP
SOLENOID
TEMPERATURE
SEN0
UNIT
FUSE BOX
a
*\T0
k IGNITION
^SWITCH
PONTIAC TCi» AND SCS CIRCUIT
(ENGINES WITHOUT ANTI-DIESELING
SOLENOID)
Chevrolet V-8
The Chevrolet V-8 uses a TCS systfem in which the vacuum
advance solenoid is energized to provide spark advance. All use
a normally-open transmission switch, an anti-dieseling sole-
noid, and a hot/cold temperature switch. On Corvette engines,
the temperature switch provides both hot and cold override of
the transmission switch to provide vacuum advance, regardless
of gear position. On other Chevrolet engines, only cold over-
ride is provided, with the hot switch serving only to light an
engine overheat light on the instrument panel. In addition, all
small-block V-8s incorporate a 20-second delay of vacuum ad-
vance when the transmission is shifted to high gear. The TCS
delay relay is normally open.
-------
»atte*y
-iGN SWITCH
ICHf STOP SOLENOID
UWOTTIE
V- IfVC*
70 StC
DEtAY KUY
1972 SMALL-BLOCK CHEVROLET
TCS DIAGRAM
Temperature switch wiring is typical of all Chevro-
let ismall block and big block) V-8s. TCS delay
relay is typical of all small block Chevrolet and
Corvette V-8s.
1972 VEGA TCS DIAGRAM
EGR System
This system is used on all 1973 General Motors cars and light
duty trucks (except Chevrolet-Luv) and ail 1972 California
and manual transmission Buicks.
In this system, exhaust gases are recirculated to reduce peak
combustion temperatures and lower the formation of oxides
of nitrogen (NO*). Control is provided by the EGR valve
which is responsive to vacuum above the carburetor throttle
valve (ported vacuum). Since the valve doesn't start to open
until approximately 3" of vacuum has developed, exhaust gas
recirculation which would cause rough idle is prevented at
idling speeds.
1972 BIG BLOCK CORVETTE
TCS DIAGRAM
Temperature switch wiring is typical of all Corvette
engines. Also big block engines do not use a TCS
delay relay.
Vega
The 1971-72 Vega TCS system is similar to that of the small
block Chevrolet V-8, except that the transmission switch and
the TCS relay are normally closed. This means that when the
TCS solenoid is energized (in low gears) it prevents vacuum
advance of the spark. EGR CONTROL VALVE
371
VALVE\SHAFT
VACUUM TO BE
CONNECTED TO
TIMED PORT IN
CARBURETOR jj
VALVE
CHAMBER
TO INTAKE
MANIFOLD
DIAPHRAGM
X—" COVER
SPRING
A
A 4TTI
ACTUATING
DIAPHRAGM
VALVE OPEN
VALVE CLOSED
VALVE SEAT
EXHAUST GAS
-------
1972 GM COMBUSTION CONTROL EQUIPMENT
1972
A.I.R.
THERMAC
AIR
CLEANER
ANTI
DIESEL
SOLENOID
TVS
TCS
SOLENOID
TVS-TCS
COMB
VALVE
SCS
TE
OVEH
swn
HOT
MP
tRIDE
rcH
COLD
CEC
WITH
DELAY
AFTER
START
TCS-SCS
DELAY
AFTER
UPSHIFT
BU1CK
All Calif.,
All 455,
All MT
All
All
350 AGS
with A/C;
350 MT
with
A/C or
HD Cool;
455 AGS,
GS,
STG-1
350 Ex.
A/C, HD
Cool;
350 AGS
with
A/C;
455 AGS,
GS,
STG-1
350 Auto
A/C Ex.
AGS with
A/C;
455 Ex.
AGS, GS,
STG-1
CADILLAC
All
All
All
All
All
CHEVROLET
Vega: All
Calif,
engines
and
RPO LI 1,
L53, L55,
ITT and
Z-28
All
Ex. Z-28,
Corvette
and some
light duty
truck L-6
engines
All
All
All
All
All
6 Cyl *
307, 350,
400
OLDSMOBILE
All
350-2 Bbl.,
455-MT,
Toro &
W-30
350-MT
Ex. A/C
HD Cool
All Ex.
350 MT
PONT1AC
All 6 cyl.
Calif.
All
All V-8 with
4 Bbl. & 307
All 4 SP
& 307
All
V-8
Ex.
4 SP &
307
All
All
All
6 Cyl.*
307
AGS - Special Grand Sport LS3; 402 CID, 140 HP TCS - Transmission Control Spark
CEC - Combined Emission Control LS5; 454 CID, 270 HP 1VS - Thermal Vacuum Switch
* has delay after start LT-1, Z-28 - 255 HP, 350 CID in Corvette, Camaro W-30 - Air Induction 455 CID
EGR - Exhaust Gas Recirculation MT - Manual Transmission
GS - Grand Sport SCS - Speed Control Spark
-------
1971 GM COMBUSTION CONTROL EQUIPMENT
1971
THERMAC
AIR CLEANER
A.l.R.
ANTI
DIESEL
SOLENOID
T.V.S.
T.C.S.
SOLENOID
T.V.S.-
T.C.S.
COMB
VALVE
T.C.S. TEMP.
OVERRIDE
HOT COLD
C.E.C.
BUICK
All
(Some models)
All V-8 All L-6
Throttle
Cracker on
V-8 manual
trans.
All 350
with A/C
or H.D.
cooling.
AU455 with
auto, trans.
All
CADILLAC
All
All
All
All
All
CHEVROLET
All engines ex-
cept those
equipped with
open element
air cleaner
All engines
equippped
with open
element
air cleaner
(part of
C.E.C.
solenoid)
(part of
C.E.C.
solenoid)
Camaro with LS3
(402) and also
auto, trans, and
A/C. Base
Corvette with A/C
& auto, trans.
Corvette w/LS5 &
A/C & auto, trans.
All
All
OLDSMOBILE
All
All 6 Cyl.
All 350
with man.
trans, w/o
A/C or H.D.
cooling
All V-8 ex-
cept 350
man. trans,
w/o A/C or
H.D.
cooling
6
cyl.
All
6 cyl.
PONTIAC
Al!
455 HO
engine
455 HO
engine
All 350,
400 & 455
V-8 except
455 HO
230-F.
85°
F.
All 250
6 cyl.
All 307
V-8
1970 GM COMBUSTION CONTROL EQUIPMENT
1970
THERMAC
AIR
CLEANER
A.I.R.
ANTI
DIESEL
SOLENOID
T.V.S.
T.C.S.
SOLENOID
T.C.S. TEMP. OVEK
HOT
.RIDE
COLD
BUICK
All
L-6
Ail 455 & 350
upper series.
All with auto,
trans.
L-6 &
455
CADILLAC
All
All
All
CHEVROLET
All engines except
153 4 cyl. aqd
engines with
open element
air cleaner
All 153 4 cyl.
and engines
with open
element air
cleaner
All
engines
All
Chevelle
Camaro
All V-8 auto, trans,
with A/C, all Mark IV.
Chevrolet
Ail V-8 auto, trans,
except Base 350
w/o A/C.
Nova
All except LS-7
Corvette
All V-8 auto, trans,
with A/C
Monte Carlo
All V-8 auto, trans,
with A/C,
LF-6 with auto,
trans., all Mark IV.
All
OLDSMOBILE
All
All
6 cyl.
All 350 with A/C
or H.D. cooling.
All 455 with A/C
or H.D. cooling
except W30 with
man. trans.
All
6 cyl.
PONTIAC
All
All 250 6
cyl., 400
V-8 and
Ram Air IV
engines
All
V-8 220° F.
6 cyl. 225" F.
V-8
85*F
6 cyl.
82°F
-------
1969 GM COMBUSTION CONTROL EQUIPMENT
I
1969
THERMAC
AIR CLEANER
A.i.R.
ANTI
DIESEL
SOLENOID
T.V.S.
1
BUICK
i
All
L-6
All 400, 430 engines and
350 upper series cars. Al!
with auto, trans.
CADILLAC
All 472
All 472 with A/C
CHEVROLET
Chevrolet, Chevelle.
Chevy li & Camarowith
auto, trans, (except
HPO L34 & RPO L35)
Corvair (all) Corvette (all)
Chevrolet, Chevelle. Chevy
II & Caniaro with man.
trans. & all RPO L34 (396,
350 H.P.) &. Camaro RPO
L35 (396,325 H.P.)
(idle stop)
AJ1 6 cyl.
with Power-
glide
OLDSMOBILE
All
350 w /
2 Bbl. carb.
All 6 cyl.
All 350 with A/C or H.D.
cooling. All 400 (except
W30). All 455 w/A/C or
H.D. cooling. All Toronado
PONTIAC
All
400 V-8 Ram
Air IV engines
All V-8
1968 GM COMBUSTION CONTROL EQUIPMENT
[—
i
1968
THERMAC
AIR CLEANER
A.I.R.
ANTI
DIESEL
SOLENOID
T.V.S.
BUICK
All V-8
All L-6 with auto, trans.
All L-6
All 400, 430 cars & 350
upper series; all with auto,
trans.
CADILLAC
All 472
All 472 with A/C
CHEVROLET
Chevrolet. Chevelle,
Chevy II & Camaro
w/auto. trans, (except
RPO L34 & Camaro
RPO L35 & engines
with open element air
cleaner.)
Corvair (all) Corvette (all)
Chevrolet, Chevelle, Chevy
II & Camaro w/man.
trans. & all RPO L34(396,
350 H.P.) & Camaro RPO
L35 (396, 325 H.P.) &
engines with open element
air cleaner
All 6 cyl.
w/Power-
glide
OLDSMOBILE
All
All 6 cyl.
All 350
with 2 Bbl.
carb.
All 350 with A/C or H.D.
Cooling. All 400 w/2 Bbl.
Carb. & A/C. All 400 w/4
Bbl. carb. (except W-30)
All 455 with A/C or H.D.
cooling
All Toronado
PONTIAC
All
All
All V-8
-------
FORD MOTOR COMPANY COMBUSTION
CONTROL DEVICES AND SYSTEMS ON 1968
AND LATER CARS
The three major combustion control devices used by Ford
Motor in the period from '68 to '72 are:
1. A dual-diaphragm vacuum-advance mechanism at the dis-
tributor;
2. A distributor vacuum control valve (sometimes referred
to as the PVS valve); and
3. A distributor vacuum advance control valve (sometimes
referred to as a deceleration valve)
With few exceptions, one or more of these devices wiil oe
found on all '68 through '72 Ford Motor cars. When the de-
vices are used with an air injection system, the system is called
a Thermactor system. Without air injection, the system is
called an IMCO (Improved Combustion) system.
Dual-Diaphragm Vacuum-Advance Mechanism
With this mechanism, control of spark advance is provided by
two independent diaphragms which work in opposition to
each other.
The advance (primary) diaphragm uses carburetor vacuum to
provide a conventional advance-retard curve when the throttle
is not closed. The retard (secondary) diaphragm uses intake
manifold vacuum which overpowers the primary diaphragm
vacuum from the carburetor under closed-throttle deceleration
or idling. This extra retard position provides better and more
complete combustion by starting ignition approximately 12
degrees later than the normal retard position of the primary
diaphragm.
DUAL-DIAPHRAGM VACUUM
ADVANCE MECHANISM
Distributor Vacuum Control Valve
This unit provides the same basic function of the General
Motors TVS valve, namely spark advance when the engine
reaches an overheat condition, such as caused by prolonged
idling. The advance increases idling speed to increase fan cool-
ing. The Ford unit differs in that it uses a ball valve (instead of
a sleeve valve). It acts directly on the primary diaphragm in
dual-diaphragm distributors or the diaphragm in single-
diaphragm distributors.
DISTRIBUTOR VACUUM CONTROL VALVE
(WITH DUAL-DIAPHRAGM) NORMAL
TEMPERATURE CONDITION-SPARK
RETARDED
Distributor Vacuum Advance Control Valve
(Deceleration Valve)
This unit is designed to provide acceptable high-speed closed-
throttle deceleration characteristics. Under the conditions
when high engine speed and a retarded spark are present, there
is the likelihood of popping or backfiring in the exhaust mani-
fold. This is especially likely when a dual-diaphragm vacuum
advance mechanism is used which provides an extreme retard
position. Accordingly, the deceleration valve is used only when
an engine is equipped with a dual-diaphragm vacuum advance
and a PVS valve, as well. In operation during closed-throttle
deceleration, manifold pressure is high enough to overcome
spring pressure causing the valve to open, allowing manifold
vacuum to reach the distributor for normal spark advance.
On small-displacement engines, the output from the decelera-
tion valve is routed directly to the primary diaphragm of the
dual-diaphragm vacuum advance mechanism.
On high-displacement engines, it is customary to route the
deceleration valve output to the vacuum advance control valve
instead of directly to the distributor.
DISTRIBUTOR VACUUM CONTROL VALVE
(WITH DUAL-DIAPHRAGM) OVERHEAT
CONDITION-SPARK ADVANCED
-------
TO
DISTRIBUTOR
1
TO
CARBURETOR
n
r?
1 kwt
i •
ii—
—o-j
• •
1 •
IJ
rmwt
TO INTAKE
MANIFOLD
DISTRIBUTOR VACUUM ADVANCE CONTROL
VALVE (DECELERATION VALVE)
AOVANCE DISTRIBUTOR MECHANISM AOVANCE
VALVE-
e
if
DIAPHRAGM
> ADJUSTABLE
SPRING
RETARD
POSITION DURING
DECELERATION
— POSITION EXCEPT
DURING DECELERATION
DECELERATION VALVE DIAGRAM
(LOW-DISPLACEMENT ENGINE)
FORD MOTOR COMPANY COMBUSTION
CONTROL DEVICES AND SYSTEMS ON 1970
AND LATER CARS
Distributor Modulator System (DMS)
The DMS is similar in function to the GM-SCS system, in that
it prevents spark advance below certain speeds, during ac-
celeration and deceleration.
The DMS consists of the following:
• An electronic speed sensor;
• An electronic amplifier and solenoid valve; and
• A thermal switch
In addition, the DMS makes use of the engine's PVS (positive
ventilation system) valve.
Speed Sensor
The sensor is a miniature generator connected to the speed-
ometer cable. Voltage output increases with car speed.
Electronic Control Modulator (Amplifier)
and Solenoid Valve
The solenoid, when de-energized, prevents spark advance (no
vacuum reaching distributor diaphragm). When car speed
readies 23 mph, the speed sensor produces enough voltage,
when amplified, to energize the solenoid, permitting carbure-
tor vacuum to reach distributor diaphragm for normal spark
advance. Slowing the car below 18 mph de-energizes the sole-
noid to provide spark retard.
Thermal Switch
This switch, located on the front door hinge pillar, is closed
when outside air temperature is below 58°F, energizing the
solenoid to provide normal spark advance regardless of car
speed.
PVS Valve
On some installations the vacuum line from the solenoid to the
distributor is routed through the PVS valve (or distributor
vacuum control valve). With this layout, engine overheat con-
ditions permit intake manifold vacuum (instead of carburetor
vacuum) to reach the advance diaphragm, increasing spark ad-
vance to provide a higher idling speed.
FORD MOTOR COMPANY COMBUSTION
CONTROL DEVICES ON 1971
AND LATER CARS
Pinto Decel Valve
This unit, not to be confused with the Distributor Vacuum
Advance Control Valve (or deceleration valve) is used on the
Pinto engine only. Instead of advancing the spark or opening
the throttle plate during deceleration (as the GM CEC solenoid
does), the decel valve supplies additional fuel-air mixture to
the engine (by-passing the carburetor fuel-air delivery) during
deceleration. When actuated, the valve prevents popping or
backfiring in the exhaust manifold. The unit is mounted on
the intake manifold and is actuated by a diaphragm responsive
to manifold vacuum.
FORD MOTOR COMPANY COMBUSTION
CONTROL DEVICE AND SYSTEMS ON 1972
AND LATER CARS
Electronic Spark Control (ESC)
The ESC system is a refinement of the DMS system used on
some '70 and '71 Ford products. The major differences are:
1. The electronic control modulator (amplifier) may have
one of four-pre-set energizing speeds and are color-coded
accordingly.
Black cuts in at 23 mph
White cuts in at 28 mph
Blue cuts in at 33 mph
Green cuts in at 35 mph
All modulator-amplifiers cut-out (open circuit to sole-
noid) when speed drops below 18 mph.
2. The modulator-amplifier is not separate from vacuum
control solenoid valve.
3. The thermal switch is in series with the primary energiz-
ing lead to the system, so system is completely.de-
TYPICAL 1972 ESC SYSTEM
A PVS valve (not shown in this example), may be
installed in series with the vacuum line from the
solenoid to the distributor to provide overheat con-
trol.
SPEED
ELECTRONIC
AMPLIFIER
-------
energized (thermal switch open) when outside air
temperatures are below 60°F.
Transmission Regulated Spark (TRS) Control System
The TRS system is similar in function to the GM TCS system
in that it prevents spark advance when the car is operating in
lower gears. However, it differs in that it allows normal spark
advance when the outside air temperature is below a certain
temperature (not when engine coolant temperature is below a
certain temperature as in the GM TCS system).
It differs from the Ford ECS system in that the ECS's speed
sensor and amplifier are replaced with a transmission switch
which completes the system's circuit to ground when the
transmission is in lower gears or "Neutral" (manuai trans-
missions), or, with automatic transmissions, when there is no
hydraulic servo pressure in third or reverse.
Like the ECS system, the thermal switch is wired in series to
the primary energizing lead to the system. Therefore, when
this switch is open (air temperature below 60°F.) the system is
de-energized, permitting spark advance.
TRS SYSTEM
On some TRS installations, a Spark Delay Valve may be used
in the vacuum line between the distributor primary diaphragm
and the carburetor port. It is a combination air restrictor and
check valve that slows down the draining of air from the
primary diaphragm (delaying spark advance), but offers little
restriction when air is draining back into the diaphragm (fast
spark retard).
The delay function occurs only during mild accelerations from
idle to 16 mph when carburetor vacuum is high.
FORD MOTOR COMBUSTION
CONTROL EQUIPMENT
During 1968 through 1971 Ford built "Therrnactor" (exhaust
air injection) and "IMCO" (IMproved COmbustion with air
injection) engines. No '72 engines used air injection.
1972
Thermostatic Air Cleaner: All engines.
Transmission-Regulated Spark (TRS): All manual transmission
Sixes and V-8 , except 240 1-bbl and 351 2-bbl.
Speed Regulated Spark (Using speed sensor): Automatic trans-
mission 240 Six and 351 V-8 (except HO).
Electronic Spark Control (ESC): All other auto-trans, engines,
i Dual-diaphragm distributor, Distributor Vacuum Control
valve, or Distributor vacuum advance control valve: some
engines (6 & V-8).
Decel Valve: All Pinto engines.
1971
Thermostatic Air Cleaner: All engines.
Therrnactor: 302 Boss, 429 Super Cobra, 460.
IMCO: Other Sixes and V-8s, Pinto 4.
Electronic Distributor Modulator: Most Sixes and V-3s with
automatic transmissions.
Dual-diaphragm distributor, Distributor Vacuum Control or
Distributor vacuum advance control valve: Some 6 & V-8
engines.
Decel valve: All Pinto engines.
1970
Thermostatic Air Cleaner: All engines.
Therrnactor: 302 Boss, 428 Police and Cobra Jet, 460.
IMCO: All Sixes, 302 & 429 (Exc. high perf.) 351 "C" & "W",
390.
Electronic Distributor Modulator: 240, 302 std., 351 4-bbl,
390 with AT.
Dual-Diaphragm distributor, Distributor vacuum control valve,
or Distributor vacuum advance control valve: Some 6 &
V-8 engines.
1969
Thermostatic Air Cleaner: All IMCO and some Therrnactor
engines.
Therrnactor: 428 Cobra Jet and 427.
IMCO: All other engines.
Dual-Diaphragm Distributor, Distributor vacuum advance con-
trol valve, or Distributor vacuum control valve: Various
combinations used on all engines.
1968
Thermostatic Air Cleaner: All IMCO and some Therrnactor
engines.
Therrnactor: All manual transmission engines, 427 with auto.
IMCO: All other automatic transmission engines.
Dual-Diaphragm Distributor. Distributor vacuum control valve,
or Distributor vacuum advance control valve: Various com-
binations used on all engines (exc. 427 AT)
CHRYSLER CORPORATION COMBUSTION
CONTROL DEVICES ON 1968
AND LATER CARS
Vacuum Control Valve
This unit, used on some engines, is similar to the Ford distribu-
tor vacuum advance control valve (deceleration valve) and per-
forms the same function: Provides vacuum spark advance, dur-
ing conditions of closed-throttle deceleration to eliminate pop-
ping and backfiring in the exhaust manifold.
During idling there is little manifold vacuum so spring pressure
keeps the valve closed, allowing carburetor vacuum to reach
distributor. Since this vacuum is weak at idling, there is no
vacuum advance.
During acceleration and steady speed, manifold vacuum
remains weak, so spring pressure keeps the valve closed. High
carburetor vacuum reaches the distributor, providing vacuum
advance.
-------
VACUUM CONTROL VALVE,
IDLING CONDITION
During closed-throttle deceleration, manifold vacuum is high,
overcoming spring pressure and opening the valve allowing
manifold vacuum to reach distributor to advance the spark.
DISTRIBUTOR SOLENOID
The Distributor Modulator system is used with a throttle stop
solenoid (see Throttle Stop Switch illustration). This is identi-
cal in function and operation to the GM anti-dieseling sole-
noid.
VACUUM CONTROL VALVE,
CLOSED-THROTTLE
DECELERATION CONDITION
CHRYSLER CORPORATION COMBUSTION
CONTROL SYSTEMS AND DEVICES ON 1970
AND LATER CARS
Distributor Solenoid (Or Distributor Modulator)
This system, used on high-displacement V-8s, consists of a
solenoid, located on the distributor between the advance dia-
phragm and breaker plate, energized by a grounding switch
incorporated in the throttle or idle stop at the carburetor. A
new "fast curb idle" adjustment screw is also incorporated at
this point.
The system permits the use of a higher-than-normal advance
curve to provide easier starting and better highway perfor-
mance, since it introduces a greatly-retarded spark at curb idle
(for reduced emission) when the solenoid is energized by the
throttle stop switch.
THROTTLE STOP SWITCH
ION CARBURETOR)
CHRYSLER CORPORATION COMBUSTION
CONTROL DEVICES AND SYSTEMS ON 1971
AND LATER CARS
Chrysler NOx System
Starting in 1971 Chrysler introduced devices to reduce nitro-
gen oxide emissions on cars for sale in California. In addition
to a higher-overlap camshaft and a lower (185°F.) coolant
thermostat, the system features a transmission-controlled oi
speed-controlled spark.
Transmission Controlled Spark System.
(Manual Transmission Cars)
This system is very similar to the Ford TRS system, in that it
uses (1) distributor vacuum solenoid control valve which
when energized, prevents carburetor vacuum from reaching the
distributor and advancing the spark. The solenoid is controlled
by (2) a thermal switch which closes when air temperature is
above 70°F. and (3) a transmission switch which closes when
the transmission is in lower gears. Thus the solenoid is ener-
gized to prevent normal advance only when the car is in a
lower gear with temperatures above 70°F.
SOLENOID ROTATES
BREAKER PLATE
WINDINGS
ARMATURE
THROTTLE
STOP
CURB IDLE
ADJUSTING
SCREW
-------
With this unit the thermal switch is used ony on early produc-
tion cars and is located in the plenum chamber.
CHRYSLER MANUAL TRANSMISSION
TCSCOMPONENTS
Speed Controlled Spark System
(Automatic Transmission Cars)
In this system, vacuum advance is cotrolled by car speed, air
temperature and, in some cases, coolant temperature. It con-
sists of a distributor vacuum solenoid control valve, a control
unit assembly (which contains a vacuum switch and a thermal
switch), and a speed switch.
CARBURETOR
CHRYSLER AUTOMATIC TRANSMISSION
SCS DIAGRAM
Solenoid Control Valve
This unit is identical to that used in the TCS system. When
energized it prevents carburetor vacuum from reaching the dis-
tributor advance diaphragm.
Speed Switch
This unit, mounted at the transmission or at the mid-point of
the speedometer cable, is closed at speeds below 30 mph
(energizing) and open (de-energizing) at speeds above 30 mph.
It is wired to the control unit assembly.
Control Unit Assembly
The assembly contains a thermal switch which is closed at air
temperatures above 70°F, open when temperatures are below
70°F. Output from the thermal switch and speed switch feed
into the assembly's control module, which, in turn, energizes
or de-energizes the solenoid control valve.
In addition, the assembly includes a vacuum switch which is
controlled by manifold vacuum. During periods of accelera-
tion, when manifold vacuum is low, the switch closes, energiz-
ing the solenoid valve, through the control module, and pre-
venting vacuum advance at the distributor.
From the above, it can be seen that the SCS prevents vacuum
advance (1) when speed is below 30 mph, (2) when air temper-
atures are above 7&F, and (3) whenever the car is accelerating.
In addition, some cars also include a separate coolant tempera-
ture vacuum by-pass valve (similar to the GM TVS) which
provides vacuum advance for faster idling when an overheat
condition exists.
Distributor Starting Solenoid
This unit, used on certain 1972 high-displacement engines, is
similar in appearance to the distributor solenoid (modulator)
used on some '70 and '71 engines. However, instead retard-
ing distributor breaker plate during idling, it advances the
breaker plate during starting. Accordingly, the idle stop switch
is eliminated, and the solenoid energized directly from the
ignition circuit through the alternator field lead and grounded
through the throttle-levers stop screw. When the throttle is
opened, after starting, the circuit is broken, returning the dis-
tributor to purely vacuum control.
EGR System
Similar in purpose to the General Motors EGR system, the
Chrysler system differs in the method used to help reduce
oxides of nitrogen (NOx) emissions. No control valve is used.
Instead, recirculation is metered by fixed orifice jets located
between the "exhaust and intake manifolds.
INCOMING FUEL-AIR
CROSS-OVER
CHRYSLER EGRSYSTEM
CHRYSLER CORPORATION COMBUSTION
CONTROL EQUIPMENT
1972
Thermostatic Air Cleaner: All engines.
Air Injection: Ail California Sixes & 400, 440 V-8s.
Distributor Solenoid (advance for start): 400 & 440 V-8s.
Exhaust Gas Recirculation: All California cars.
Transmission Controlled Spark: All California Cars with Ml .
Speed Controlled Spark: All California cars with auto, trans.
1971
Thermostatic Air Cleaner: All except 340,426 Hemi, 4^0 Six-
Pack.
Distributor Solenoid (retard when throttle closed): 383,440
(exc. with Six-Pack).
Idle stop solenoid (anti-dieseling): High performance 340, M0,
and 426 Hemi.
SPONGE
TRANSMISSION
SWITCH
THERMAL
SWITCH
SOLENOID
VACUUM VALVE
-------
Transmission Controlled Spark: All California man. trans, cars.
Speed Controlled Spark: All California auto, trans, cars.
1970
Thermostatic Air Cleaner: All except 340, 426 Hemi ana 440
Six-Pack.
Distributor Solenoid (retard when throttle closed): 3S3, 440.
Idle Stop solenoid (anti-dieseling): High perf. 440 & 426
Hemi.
1968-1969
Vacuum Control Valve: All
AMERICAN MOTORS COMBUSTION CONTROL
DEVICES AND SYSTEMS ON 1970
THROUGH 1972 CARS
Deceleration Valve
This unit is used only on 1970 199 and 232 Sixes and the 390
V-8, when equipped with manual transmissions. In operation
and function it is quite similar to the Chrysler vacuum control
valve: Provides vacuum spark advance at the distributor dia-
phragm, during conditions of closed-throttle deceleration, to
eliminate popping and backfiring in the exhaust manifold.
Like the Chrysler valve, the deceleration valve features a screw
adjustment to vary spring pressure (to adjust the amount of
time vacuum is available at the distributor).
»mom o
-------
Open Closed
Below
160° F
Closed
COOLANT TEMPERATURE OVERRIDE
SWITCH VACUUM CIRCUIT
AMERICAN MOTORS COMBUSTION
CONTROL EQUIPMENT
1972
Thermostatic Air Cleaner: All engines.
Air-Guard (air injection): All V-8 engines with auto, trans.
Transmission Controlled Spark: All manual transmission en-
gines.
Speed Controlled Spark: All automatic transmission engines.
19T1
Thermostatic Air Cleaner: All V-8 engines.
Air-Guard (air injection): All V-8s with manual trans.
Transmission Controlled Spark: All manual transmission en-
gines.
Speed Controlled Spark: All automatic transmission engines.
1970
Thermostatic Air Cleaner: All V-8 engines.
Air-Guard (air injection): 304, 360, 390 engines with man.
trans.
Dual-Diaphragm Distributor: All except 232 with auto, and
late production 390.
Deceleration valve: 199, 232 and 390 with manual trans.
1968-1969
Thermostatic Air Cleaner: All V-8s.
Air-Guard (air injection): 290, 343, and 390 with man. trans.
EVAPORATIVE EMISSION CONTROL SYSTEMS
(EEC) ALL MAKES 1970-72
The purpose of the EEC system is to prevent the emission of
fuel vapors (HC) into the atmosphere. This requires a fuel
system that is totally-sealed. However, when a fuel system is
sealed, provisions must be made for conditions such as relief
from pressure build-up from vapors or fuel expansion, vacuum
caused by fuel consumption, etc. Providing for these and other
conditions requires considerable modification of the fuel sys-
tem, and, of course, the modifications vary from manufacturer
to manufacturer and year to year. The EEC systems, intro-
duced in 1970, were installed only on cars built for sale in
California. EEC systems were installed in '71 and later on all
domestic cars. (The system used in 1970 was available as an
extra cost option on some GM cars).
Fuel Expansion Provisions
Thermal expansion of fuel (caused by high air temperatures)
can cause unacceptable levels of pressure in a sealed fuel tank.
Accordingly, an air chamber or space in the tank must be
provided into which the fuel and fuel vapor can safely expand.
In American Motors cars and '70 and '71Chrysler Corporation
cars a fuel expansion tank is mounted inside the fuel tank.
Small holes at the bottom of the fuel expansion tank allow
fuel under pressure to flow, until inner tank and fuel tank
pressures are balanced.
Vf NT l IN*
V 8 AUTOMATIC
TRANSMISSION
FUEL VTv
EXPANSION \\
AMERICAN MOTORS FUEL
EXPANSION TANK
In place of a vented tank, 1971 General Motors cars use an air
trap chamber inside the tank (essentially a tank with no bot-
tom) to accomplish the same purpose.
EXPANSION VOLUME
DRAINS
FUEL TANK
1971 GM AIR TRAP CHAMBER
The most common method of providing for fuel expansion is
to locate the fuel filler tube outlet in the tank well down in
the tank so when fuel is added to the level of the outlet, no
more fuel can be added, leaving a trapped volume of air above
the fuel, for fuel expansion. Since the chamber is usually
vented (to the rest of the system), pressure from the chamber
could escape (reducing needed expansion space). On some
-------
Ford and Chrysler cars, a valve in the vent line is normally
closed during filling but opens when normal vent pressure is
present. On Chrysler the valve is called an Overfill Limiting
valve. On Ford, it is part of a three-way valve (see Pressure-
Vacuum Relief section).
ber of the tank). However, when pressure or vacuum exceeds
certain limits, spring pressure is overcome to permit air to
enter or escape from the system.
1972 CHRYSLER OVERFILL
LIMITING VALVE
Pressure-Vacuum Relief Provision
In a sealed system, pressure or vacuum relief is needed to
provide for thermal expansion and contraction of fuel, air and
fuel vapors and by fuel consumption.
Two-Way Fuel Filler Cap
One method is to incorporate a combination pressure and vac-
uum relief valve in the filler cap. Excess pressure is vented to
the atmosphere.
FORD 3-WAY VALVE
Pressure-Vacuum Relief Valve
This valve, found in many GM cars which do not use a vented
filler cap, provides a point in the fuel line system at which air
can escape or enter under tank pressure and vacuum con-
ditions. It is located in the line between the liquid-vapor
separator and the charcoal canister.
DIAPHRAGM
SPRING
GASKET
VENT ROUTING
VACUUM il
RELIEF T*
VALVE
CLOSED
PRESSURE
RELIEF VALVE
CLOSED
TWO-WAY FUEL FILLER CAP
Under tank vacuum conditions, the valve in the cap opens to
admit air into the tank. At all other times the cap is sealed.
Three-Way Valve (Ford)
This valve is normally closed (to retain space in the air cham-
PRESSURE-VACUUM RELIEF VALVE
Canister Demand Valve-Relief Valve
This unit, used in the 1970 Pontiac, provides pressure and
vacuum relief in a pair of valves located in the top of the
carbon canister. Under pressure from the fuel tank vent line,
the demand valve will raise, permitting pressure to escape into
the canister. Under vacuum conditions, the umbrella-type
relief valve opens, allowing filtered air to be drawn into the
vent line and back to the tank.
\
PRESSURE VACUUM
RELIEF VALVE
CARBON CANISTER
-------
VACUUM SIGNAL PORT , VAPOR TO P.C.V. VAlVE
COVER-] j
-VAPOR FROM FUEL TANK
SPRING
BODY COVER —i
RESTRICTIONS -
CARBON
CANISTER DEMAND
VALVE-RELIEF VALVE
Liquid Fuel Retention
Liquid fuel must be prevented from flowing uncontrolled from
the fuel tank to the vapor canister. To function properly, the
system's vent lines must be kept free of liquid fuel (caused by
sloshing or tank inclination) or heavily-saturated fuel vapors
likely to cause fuel condensation in the lines. The most com-
mon device to prevent this is the liquid-vapor separator,
mounted at the top of the fuel tank or close to it. While the
separators used vary in shape and type, all have the same char-
acteristics: a large amount of exposed surface to encourage
condensation of vapor, a high point at which the lightest
vapors can escape into the vent, and a low point from which
liquid fuel can be returned to the fuel tank.
VAPOR
TUBE
MULTI-TUBE-TYPE LIQUID-VAPOR
SEPARATOR
Overflow Float Check Valve
(AM — except Gremlins)
This float valve closes when its chamber becomes filled wiih
liquid fuel (such as caused by parking on an extreme incline)
preventing it from passing into the vent line. A vacuum release
valve is incorporated at the top of the float chamber to relieve
internal vacuum which would otherwise tend to hold fuel in
the chamber when the tank is leveled.
v/////////k
y/ZZZZZZJ/,
&
FLOAT
£
y-
5
W
TO
FUEL TAN
VENT LINE
TO ENGINE
COMPARTMENT
AM OVERFLOW FLOAT CHECK VALVE
LIQUID-VAPOR SEPARATOR
Vapor Storage And Purging
The constant evaporation of fuel within the fuel tank develops
system pressure, which for good emission control should not
be continually discharged into the air. One method of prevent-
ing this is to provide surfaces on which the fuel vapor particles
can attach themselves. The inner exposed surfaces of the fuel
tank (and of some liquid-vapor separators) do provide enough
surface to achieve this.
Crankcase Vapor Storage
One method of providing additional storage space for vapor is
to vent the fuel tank to the engine crankcase through the
engine valve cover. When the engine is started, stored vapors
are drawn into the engine induction system through the PCV
valve. This "purges" the crankcase surfaces of stored vapor so
VAPOR-VENT
LINES
THERMAL-EXPANSION
VOLUME TANK
VACUUM
RELIEF FILLER CAP
CAR3URETOR
VENT LINE
CRANKCASE v*PO«
SEPARATOR
-------
they are ready for more vapor storage when the engine is
turned off.
CRANKCASE VAPOR STORAGE SYSTEM
('70 CHRYSLER)
Carbon Canister Vapor Storage
A different method is to vent the tank to a canister containing
activated charcoal. The typical canister contains about a
pound of carbon which provides an exposed surface area of
about one-quarter square mile, enough to store almost a cup of
liquid fuel when vaporized.
Purging Methods
In the simplest of canister hook-ups, purging occurs through a
vent line from the canister to the air cleaner. This provides a
variable purge since the amount of purging is proportional to
air flow through the air cleaner.
By using intake manifold vacuum and a small fixed orifice on
the canister outlet, purging through the outlet is controlled at
a fixed rate, known as constant purge. Still another method is
used in the '70 Pontiac. (see previous illustration). A demand
valve at the canister does not allow purging until a certain level
of vacuum occurs at the canister outlet. A variation is where
intake manifold vacuum controls a valve at the canister to
allow purging to take place. This results in demand purging.
Constant purging is in recognition of the fact that little air
flow through the canister is needed to provide adequate purg-
ing. Demand purging is designed to insure that purging occurs
during conditions of engine operation which will be least af-
fected by purge air-fuel mixtures on the performance and
driveability of the engine.
CANISTER USING CONSTANT PURGE
CANISTER USING CONSTANT AND DEMAND
CANISTER HOOK-UP FOR VARIABLE PURGE PURGE (HEAT SHIELD ALSO SHOWN)
-------
EVAPORATION EMISSION CONTROL SYSTEMS
By Make and Year -1970 Through 1972
1970
1971
1972
S
o
FORD
CHRYS
<
O
FORD
CHRYS.
S
<
FORD
CHRYS
<
FUEL EXPANSION
PROVISION
Inner Tank or Trap
All
All
All
(3)
(3)
Air Chamber Fuel Tank
All
All
All
All
Grem.
All
All
All
Grem.
Overfill Check Valve
(1)
All
All
PRESSURE - VACUUM
RELIEF PROVISION
2-Way Cap
Some
All
All
All
All
All
All
All
All
Ventline P-R
Relief Valve
Some
All
All
3-Way Valve
All
Canister Demand -
Vacuum Relief Valve
(2)
LIQUID FUEL RETENTION
l iquid Vapor Separator
All
All
All
All
All
All
All
All
All
()veiHow l loal Valve
All
(3)
(3)
V \POU STOKUil
1 'lUllki'.IM'
Some
All
All
All
All
All
I'.iiUmi I'aiusUM
All
All
All
All
.All
All
(1) P.iii of .?-\Vay Valve (2) 1^70 Pontiac (3) All Except Gremlin
-------
APPENDIX I
-------
BIBLIOGRAPHY
Crouse, William Harry
Automotive Emissions Control (by Wm. H. Crouse, New York,
McGraw-Hill, 1971).
Gargano Promotions Division
"Vehicle Emissions Control" 2nd Edition
American Consolidated Industries, Inc., 1973.
Glenn, Harold T.
"Glenns Emissions-Control Systems"
Henry Regnery Co., Chicago, 1972.
Mitchell Manuals, Inc.
Exhaust Emissions Control Manual
1973 Supplement
Mitchell Manuals, Inc., San Diego, 1973.
Mitchell Manuals, Inc.
"Emissions Control Training Program"
Student and Instructors Manuals
Mitchell Manuals, Inc., San Diego, 1974.
Chilton Book Company
Chiltons Motor Age Professional Emission Diagnostic
and Safety Manual
Chilton Book Company, Radnor, Pennsylvania
Patterson, Donald J.
Emissions From Combustion Engines and Their Control,
(by D.J. Patterson and N.A. Henein, Ann Arbor,
Michigan, Ann Arbor Science Publishers, 1972).
Post, Daniel
Non-Catalytic Auto Exhaust Reduction, (Park Ridge,
N.J., Noyes Data Corp., 1972).
Ranney, Maurice William
Catalytic Conversion of Automobile Exhaust, (by
John McDermott, Park Ridge, N.J., Noyes Data Corp.,
1971).
Springer, George S.
Engine Emissions; Pollutant Formation and Measure-
ment. (edited by G.S. Springer and D.J. Patterson,
New York, Plenun Press, 1973).
-------
388
BIBLIOGRAPHY (CONT.)
Manuals and Booklets
Chevrolet - "1975 New Product Information" Product Assurance
Department - Chevrolet Motor Division. Detroit, Michigan.
Chevrolet - Emission Control Systems, Product and Safety
Activities Department, Chevrolet Motor Division, Detroit,
Michigan.
Chevrolet - Emission Control, Theory and Diagnosis, 1971
General Motors Corporation #ST. 343-71; Chevrolet
Motor Division, Detroit, Michigan.
Chrysler - "1973 Emission Controls", Chrysler Corporation
Regional Office Denver, Colorado ATTN: Dick Leitz.
General Motors, Emission Control Systems Maintenance Manual;
Service Section, General Motors Corporation, Detroit,
Michigan, 48202.
1973 Supplement to General Motors Emission Control System
Maintenance Manual; Service Section, General Motors
Corporation, Detroit, Michigan, 48202.
National Service Department, Ford Parts Division, Ford
Marketing Corporation; Livania, Michigan 48151.
A. Autolite - Engine Emission Control System
Form #AUD-7528-G.
B. Motorcraft - Vehicle Emission Control System
Form #AUD-7528-J.
C. Motorcraft - Vehicle Emission Control System
1973 - Supplement; Form #7528-J3.
Power Service Training, Part III Emission Control Service.
Service Section, General Motors Corporation, Detroit,
Michigan, 48202.
The Story of Gasoline, Ethyl Corporation Petroleum Chemicals
------- |