Student's Workbook for Vehicle Emissions Control Training

x  EPA-450/3-77-035'
 \Voven her 1977
                          STUDENT'S WORKBOOK
                         FOR VEHICLE EMISSIONS
                               CONTROL TRAINING
                                             *.»• " •% -*•
                                             •t. ».'• •'.»',* /i' •.
                                             ; •'•:::'?'•:••• -r-:
        U.S. ENVIRONMENTAL PROTECTION AGENCY
             Office of Air and Waste Management
          Office of Air Quality Planning and Standards
         Research Triangle Park, North Carolina 27711

-------
                                 EPA-450/3-77-035
 STUDENT'S  WORKBOOK
FOR VEHICLE EMISSIONS
    CONTROL TRAINING
                   by
           B.D. Hayes, Project Director
        M.T. Maness, Associate Project Director
         R.A. Ragazzi, Principal Investigator

          Department of Industrial Sciences
            Colorado State University
           Fort Collins, Colorado 80523
           EPA Grant No. T900621-01-0

         EPA Project Officer: Bruce Hogarth
                Prepared for


     U.S. ENVIRONMENTAL PROTECTION AGENCY
         Office of Air and Waste Management
       Office of Air Quality Planning and Standards
        Control Programs Development Division
       Research Triangle Park, North Carolina 27711

                November 1977

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Copies of this publication are available free of charge to Federal employees,
current contractors and grantees, and nonprofit organizations - as supplies
permit - from the Library Services Office (MD-35),  Environmental Protection
Agency, Research Triangle Park, North Carolina 27711; or, for a fee, from
the National Technical Information Service, 5285 Port Royal Road, Springfield,
Virginia 22161.
This report was furnished to the Environmental Protection Agency by the
Department of Industrial Sciences, Colorado State University,  Fort Collins,
Colorado, 80523, through Grant No. T900621-01-0. The contents of this
report are reproduced herein as received from Colorado State  University.
The opinions, findings,  and conclusions expressed are those of the authors
and not necessarily those of the Environmental Protection Agency. Mention
of company or product names is not to be considered as an endorsement
by the Environmental Protection Agency.
                        Publication No. EPA-450/3-77-035
                                     11

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                              Foreword

     Motor vehicle emissions control is becoming an increasingly large
part of each person's life who is associated with the automotive indus-
try.  This is particularly true of the people that have to service
today's motor vehicles.  Since the beginning of motor vehicle emissions
control in the mid-1960's, a number of different emissions control
systems have evolved.  These systems have been augmented with a variety
of other devices that only add to the cluttered and confusing array of
wires, plumbing and vacuum hoses that are found under the hood of most
cars today.  It is of little wonder that a large number of service
people feel intimidated and confused when they look under the hood of
today's cars.
     It is the intent of this student workbook to explain each basic
emissions control system and some of the more common devices found on
today's cars.  Each discussion and exercise will be concerned with the
basic concept (what does the system do?) of a certain system.  If a
service technician can understand the concept of a system and how it
relates to driveability and emissions, he is on the right road for
increasing profits, satisfying customers, and aiding in the effort
toward clean air.
     Another advantage to learning the concepts of emissions control
systems is that  the same system concept applies to nearly every car.
This reduces some of the confusion that results from studying Ford's
system today, AM's system tomorrow and Chrysler's the day after.  Once
a concept is understood that knowledge can be applied to nearly all
cars.  The hardware may be somewhat different in appearance, but the job
it is performing is essentially the same.
     We hope these booklets will help remove some confusion and aide the
mechanic in the performance of his job.
                                  iii

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                     ACKNOWLEDGMENTS






The Motor Vehicle  Emissions Control Staff of the Department



of Industrial  Sciences  at Colorado State University would



like to acknowledge the efforts extended by the Environmental



Protection Agency,. Research Triangle Park, for their contribu-



tions to the development of this booklet.






A special thanks must be extended to the automotive vehicle



equipment and  parts manufacturers for their cooperation and
                  •


assistance in  the  development of this training material.
                           IV

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                         Student's Workbook






     The Student Workbook is designed to lead the student through the




key points of each emissions control system.



     Each basic emissions control system presented will have the follow-




ing information provided.






PART IDENTIFICATION



     The basic parts of each emissions control system will be identified



Physical identification of each part involved in a system is important.



The identification of parts related to a specific system allows a person



to look under the hood of a car and "see" systems, rather than a confus-



ing mass of hoses, switches, and other devices.   A very brief descrip-



tion of what the part does is also provided.






SYSTEM OPERATION



     In this section the individual parts of each system are explained.



The total system is studied from a functional viewpoint which tells what



it is supposed to do.  The way the system operates is explained, showing



flow paths, and variations due to different modes of engine operation.



Understanding how a system operates makes troubleshooting and correcting



problems a much simpler task.






SYSTEM CONTROL



     This section deals with the control of a system.  Many emissions



control systems are controlled by various temperature devices and/or



sources of engine vacuum.  This section will deal with how a particular



system is or may be controlled.  Understanding of this portion also



enhances the troubleshooting ability of the service technician.

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SYSTEM EFFECTS  ON HC-CO AND DRIVEABILITY



     This section deals with  the  effect of the system on emissions and



driveability.   It explains how  and  why the system affects emissions and



driveability.   It is  hoped this section will build an appreciation of



the need for proper operation and adjustment of any system that affects



the internal combustion engine.





W6RKSHEETS



     For each  system  a basic  worksheet is included.  The purpose of this



worksheet is to enforce the previously covered material.  The use of



hands-on and the effects  that establishing different system conditions



have on emissions are extremely important tools in the learning process.



Incorporated with the worksheets  are quick operational checks that can



be made on each system.

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                         CONTENTS


Unit 1 - Cause and Effect	1
     Hydrocarbons 	  1
     Carbon Monoxide  	  2
     Oxides of Nitrogen 	  2
Unit 2 - Infrared Exhaust Gas Analyzer	5
     Parts of Analyzer	5
     Causes for various HC-CO Meter Readings  	  6
     Worksheet  . .  . .-	11
Unit 3 - Ignition and Carburetion	13
     Idle Mixture Adjustments - CO Emissions  	 13
     Idle Mixture Adjustments - HC Emissions  	 14
     Advancing Ignition Timing - HC Emissions 	 15
     Worksheet	16
Unit 4 - Positive Crankcase Ventilation 	 17
     Crankcase	17
     Ventilation	18
     Closed PCV System	18
     Flow of Blowby Gases	19
     Purpose of PCV Valve	20
     Control of HC,  CO and Driveability	21
     Operational Checks 	 22
     PCV Valve Checks	24
     Worksheet	24
Unit 5 - Thermostatic Air Cleaners	25
     Types of TAG Systems	25
     Parts Common to TAG Systems	26
     Major Parts of Thermostatic Type	26
     Major Parts of Vacuum Motor Type	27
     Operating Modes Common to TAG Systems  	 27
     Operation and Control of Thermostatic Type 	 28
     Operation and Control of Vacuum Motor Type 	 30
     Emissions and Driveability 	 33
                            vn

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     Operational  Checks  	  34
     Worksheet	36
Unit 6 - Air Injection Systems  	37
     Main Components  	37
     Air Flow	38
     Diverter Valve Operation 	  38
     Pressure Buildup Diverter Valve  	  40
     Purpose of Air Switching Valve 	  40
     Gulp Valve	41
     Control of HC, CO and Driveability	42
     Operational Checks  	  43
     Worksheet	46
Unit 7 - Fuel Evaporation Control	47
     Components of System 	  47
     Operation of System	48
     Methods to Purge Fuel Vapors	50
     Operation of Carburetor Fuel Bowl Vents	51
     Control of HC, CO and Driveability	52
     Maintenance Checks  	  53
     Worksheet	53
Unit 8 - Exhaust Gas Recirculation	55
     Purpose of EGR Valve	55
     Control Components  	  56
     Ported Vacuum EGR with CTO Switch	57
     Venturi Vacuum EGR with CTO Switch	58
     Ported Vacuum EGR with Back Pressure Sensor   	  59
     Control of HC, CO,  NO  and Driveability	61
                          X
     Operational Checks  	  63
     Worksheet	67
Unit 9 - Spark Control Systems	69
     Purpose for Retarted Spark Timing at Idle 	  69
     Parts of Transmissions Control Spark System   	  70
     Operation of Transmissions Controlled  Spark   	  70
       System
                            Vlll

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     Transmission Controlled Spark System with 	 72
       CTO Switch
     Transmission Controlled Spark System with 	 73
       Hot and Cold Temperature Switch
     OSAC Valve	74
     Control of HC, CO, NO  and Driveability	75
                          X
     Operational Checks  	 76
                                                              t,
     Worksheet	79
Unit 10 - Catalytic Converter Systems	81
     Purpose of Catalytic Converter  	 81
     Construction of Converter 	 82
     Engine Performance Effects Catalytic Converter  .... 83
       Operation
     Purpose of Protection Systems 	 83
     Operation of Protection Systems 	 84
     Purpose of Exhaust System Heat Shield 	 85
     Use of Unleaded Fuel	86
     Control of HC, CO, NO  and driveability	86
                          J*±
     Worksheet	88
                              IX

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                           STUDENT WORKBOOK
                           Cause and Effect
                                Unit 1

NOTES:
     Throughout this course of study, the terms, Hydrocarbons  (HC),
Carbon Monoxide (CO) and Oxides of Nitrogen will be used frequently.
These are terms that should be understood by today's service technician.
These terms appear in all information relating to emissions control.
They appear on the majority of VEHICLE EMISSIONS CONTROL INFORMATION
labels found under the hood of today's cars.  A service technician must
understand these terms if he is to properly adjust today's automobiles,
and properly use today's test equipment.  Knowledge of these terms also
aids the technician in giving explanations to customer-related questions.

A. Hydrocarbons
   Hydrocarbons, abbreviated HC, are the chemical components that make
   up all petroleum products.  This includes gasoline, fuel oil, and
   lubricating oil.  In regard to today's cars, hydrocarbon (HC)
   emissions indicate gasoline that did not burn.  This may be expressed
   as unburned hydrocarbon emissions.
           HYDROCARBONS
              PPM.
                                   This meter shows us how much
                                   unburned gasoline (HC) is leaving
                                   the engine and being exhausted to
                                   the air.
           Figure 1-1

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Hydrocarbon emissions contribute to the following conditions.
1. The formation of photochemical smog.
2. Eye irritation
3. Health hazards - some unburned hydrocarbons are suspected
of causing cancer and other health related problems.

B. Carbon Monoxide
Carbon Monoxide (CO) results from incomplete comubstion. In order to
burn a given amount of gasoline completely, a certain amount of air
must be present. If these is too much fuel present for the amount of
air, carbon monoxide (CO) emissions increase. As the proper amount
of air becomes available for a certain amount of fuel - CO emissions
decrease.
ZEE:
^.j-r^g.^
^-^T^^3~T~rr^s^ "N
*rT- """""*-
-------
process in the engine. Seventy-eight (78%) percent of the air we

breathe is made up of nitrogen. When this air is drawn into the

engine and burned at temperatures greater than approximately 2500°F,

NO or oxides of nitrogen are formed.
Ji

Instruments are available that read NO emissions. Because
of their high cost, they are not usually found in automobile
service facilities.

Oxides of nitrogen (NO ) emissions contribute to the following condi-
J^

tions.

1. NO + sunshine and hydrocarbons form photochemical smog.
Ji

2. NOX contributes to the dirty brown color associated with
photochemical smog.

3. Ozone (0,) results from chemical reactions involving NO .
j X

a) Ozone contributes to the smell associated with
photochemical smog.

b) Ozone also acts as an irritant to the eyes and lungs.

c) Ozone causes rubber products to rapidly deteriorate
and is harmful to many types of plants.
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STUDENT'S WORKBOOK
Infrared Exhaust Gas Analyzer
Unit 2
Introductory Notes:
A. Explain the basic parts of the infrared exhaust gas analyzer,
Figure 2-1
Label each main part listed,
-------
B. Figures 2-2 through 2-10 are exhaust gas analyzer readings. List the

possible causes for the readings shown.

NOTES:
rOROCARBONS
PPM.
Figure 2-2
1.
a)
b)
Lo
Scale
CARBONl MONOXIDE
PERCENT
Lo
Scale
NOTES:
-------
Figure 2-3
2. Symptoms - Rough engine idle

1)
Hi
Scale
2)

3. Symptoms - Rough idle
a)
Hi
Scale
1)

3)
ON MONOXIDE
PERCENT
Lo
Scale
Figure 2-4
NOTES:
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HYDROCARBONS
PPM.
X CARBON MONOXIDjK '""
PERCENT
Figure 2-5
331
,^^
V^-~~~~~~ Hi r~ •"-^^ J*, ^Xi> ^
-------
^o^
nrrr^st%
lliv»*JLZn* *
CARBON! MONOXIDE
PEpCEjNT
Figure 2-7
RBONt MONOXIDE
PERCENT
6. Symptoms

a)
- Engine surging, 1500 rpm
Lo
Scale b)
LO
Scale
7. Symptoms - Engine surging, 1500 rpm
LO
Scale
LO
Scale
Figure 2-8
NOTES:
-------
Figure 2-9
8. Symptoms - Black smoke, 2500 rpm

a)
Lo
Scale
1)
2)
3)
4)
9. Symptoms - Occasional miss, 1500

rpm

a)
Lo
Scale
b)
Lo
Scale
Figure 2-10
10
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Fill out the following worksheet as you perform the checks.
Engine Speed
0
0
Idle
Idle
Idle
Idle
Worksheet
Test Conditions
Warm up - Zero and Span Analyzer
Remove gas cap. Hold probe next to
filler neck. Which meter indicates
unburned gasoline?
Record HC and CO for reference
reading.
Remove and ground one spark plug
wire.
Remove air cleaner unit.
Partially close choke.
HC
(PPM)
—

CO
(%)
—

11
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STUDENT'S WORKBOOK

Ignition and Carburetion

Unit 3
Introductory Notes:
A. Explain how carburetor idle mixture adjustments affect CO emissions.

1. What are CO emissions directly related

to?
CO
%
7.0-
6.0-
5.0-
4.0-
3.0-
.0
1.0-
n •»

A B C 0
FACTORY l/» TURN 1/2 TURN V* TURN
SPECS RICH RICH RICH
Figure 3-1
Figure 3-1 has points marked A-D.

Explain what each of these points

represents.

a)
b)
c)
d)
13
-------
NOTES:
B. Explain how carburetor idle mixture screw adjustments affect HC

emissions.

1. What causes more unburned fuel to be

exhausted as the air/fuel mixture

becomes richer?
HC
PPM
300-
&OU
?00'
150-
100-
50

FACTORY I/4TURN 1/2 TURN 3/4TURN
SPECS RICH RICH RICH
Figure 3-2
Figure 3-2 has points marked A-D.

Explain what each of these points

represents.

a)
b)
c)
d)
14
-------
C. Explain why advancing ignition timing increases HC emissions.
1. Explain why HC emissions increase as
ignition timing is advanced.
HC
PPM
300
250-
200
150
100-
50-
Tl
FACTORY »5'TIMWG tlO* TIMING *I5- TIMING
9PECS ADVANCE ADVANCE ADVANCE
Figure 3-3
Figure 3-3 has points marked A-D.
Explain what each of these points
represents.
a)
b)
c)
d)
15
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Fill out the following worksheets as you perform the tests.

IGNITION AND CARBURETION

WORKSHEET
Engine Speed
Idle (manufac-
turer 's specs)
Idle - maintain
manufacturer ' s
recomended
idle speed

Idle - maintain
manufacturer ' s
recommended
idle specs
Test Conditions
Carburetor set at manufacturer ' s
specs.
1/4 turn rich on idle mixture
adjustment screw (s)
1/4 turn rich on idle adjust-
ment screw (s)
1/4 turn rich on idle adjust-
ment screw (s)
1/4 turn rich on idle adjust-
ment screw (s)
Reset idle mixture adjustment
screws to manufacturer ' s
specs.

Timing set at manufacturer ' s
specs
Advance timing* 5°
Advance timing 5°
Advance timing 5°
Advance timing 5°
Reset timing to manufacturer's
specs
HC
(PPM)

CO
(%)

16
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STUDENT'S WORKBOOK
Positive Crankcase Ventilation System
Unit 4
Introductory Notes:
A. Define the term "CRANKCASE."
List the areas that are part of the crankcase,
1.
2.
3.
CLOSED SYSTEM
Figure 4-1
Draw arrows to crankcase areas,
17
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B. Explain what is meant by the term "VENTILATION."

List the problems blowby gases can cause if the crankcase is not

ventilated.

C. List the four main parts of the "closed" PVC system.

4.
CLOSED SYSTEM
Figure 4-2
Label the four main parts of the closed PCV system.
18
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D. Explain the flow of blowby gases in the closed PCV system.
Notes:
CLOSED SYSTEM
Figure 4-3
Show the normal flow path of
blowby gases and fresh air in
the closed PCV system.
CLOSED SYSTEM
Figure 4-4

Show the flow of blowby gases
during full throttle operation.
Notes:
19
-------
E. Explain the purpose of the PCV valve.
JJTRJNO
OR MOVE
Figure 4-5
MOVE BOOT
SPRING
n_
Figure 4-6
What engine conditions correspond to
this PCV valve position?
What engine conditions correspond to
this PCV valve position?
20
-------
(MIDDLE POSITION)
VALVE
SPRMG
PLUNGER
OR VALVE
What engine conditions correspond to

this PCV valve position?
Figure 4-7

F. Explain the effect the PCV system can have on HC and CO emissions and

driveability?
MUVE STUCK OPEN
BODY
TO
MANIFOLD
VACUUM
Figure 4-8
1. List the conditions a PCV valve

stuck in the maximum flow position

causes.

a)
b)
c)
d)
21
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SLUDGE &
OIL DEPOSITS
VALVE STUCK CLOSED

\£
PLUNGER
2. List the conditions a PCV valve

stuck in the minimum flow position

could cause.

a)
b)
c)
Figure 4-9
G. List the reasons for always checking the manufacturer's service

manual.

d)
H. PCV System Operational Checks.

1. Figure 4-10 shows a vacuum draw test being performed. List the

basic steps of this procedure.

a)
PCV
Figure 4-10
b)
0
22
-------
Explain how you would know if the PCV system were operating

properly.
2. Figure 4-11 shows a crankcase vacuum draw test being performed

using the inclined ramp and ball tester. List the basic steps for

performing this test.
PCV
INCLINED RAMP
8 BALL TESTER
a)
b)
c)
Figure 4-11

Explain how you would know if the PCV system is operating properly.
3. Figure 4-12 shows a crankcase vacuum draw test being performed

with an adjustable PCV system tester. List the basic steps

required to perform this test.
a)

e)
Figure 4-12
23
-------
Explain how you would know if the PCV system were operating

properly.
I. PCV Valve Checks

1. Figure 4-13 shows a PCV valve being tested. List the basic steps

required to perform this test.

e)
Figure 4-13

List the probable cause of no vacuum being felt at step e)
Fill out the following worksheet as you perform the checks.
Engine
Speed
Idle
Idle
Idle
Idle
Test Condition
VACUUM DRAW TEST
Place a sheet of paper over oil
filler hole
VACUUM DRAW TEST
Inclined Ramp and Ball
VACUUM DRAW TEST
Adjustable Tester
PCV VALVE TEST
Pass

Fail

24
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STUDENT'S WORKBOOK

Thermostatic Air Cleaners

Unit 5
INTRODUCTORY NOTES:
A. Identify the two types of air cleaners shown below,
Figure 5-1
Figure 5-2
25
-------
B. List the parts that are common to both systems,

c)
Label the parts that are common to

both systems.
Figure 5-3

C. Identify the parts of the thermostatic air cleaner,

a)
b)
c)
THERMOSTATIC TYPE
Figure 5-4
26
-------
D. Identify the parts of the vacuum motor system.

. a)
VACUUM MOTOR
TO EXHAUST
MANIFOLD
SHROUD
b)
c)
d)
Figure 5-5

E. Identify the three operating modes common to both types of air

cleaners.

1. _ _ _ mode,

List the temperature conditions

necessary for this mode of

operation. Draw in the air flow

path for this mode.
TO EXHAUST
MANIFOLD SHROUD
Figure 5-6
2. mode

List the temperature conditions

necessary for this mode of

operation. Draw in the air flow

path for this mode.
Figure 5-7
27
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3. mode.
List the temperature conditions
necessary for this mode of
operation. Draw in the air flow
path for this mode.
Figure 5-8
F. List the events that control the thermostatic air cleaner from cold
startup through normal operating temperature.
1. Below approximately 100°F the
thermostat is retracted.
a) Explain how the damper assembly
___^___^___^^_^^^^^_^^^_ is positioned.
INCOMING AIR BELOW SPECIFIED
TEMPERATURE (APPRO* 100°)
Figure 5-9
oo
oo
oo
oo
oo
oo
b) Is heated air or cold air
allowed into the carburetor?
c) Explain when and how the intake
air is preheated.
28
-------
APPROXIMATELY 105 F
Figure 5-10
APPROXIMATELY 130 F
2. At approximately 105°F, the thermo-

stat begins to expand.

a) Explain how the damper assembly
is positioned.
b) Is heated or cold air allowed to
enter the carburetor?
3. At approximately 130°F, the thermo-

stat has expanded to full length.

a) Explain how the damper assembly
is positioned.
b) Is heated or cold air allowed to
enter the carburetor?
Figure 5-11
29
-------
4. Label the vacuum override motor.

a) During what engine condition
will the vacuum motor allow cold
air to enter the carburetor?
Figure 5-12

G. List the events that control the vacuum motor air cleaner.

1. With the engine shut off, what mode

should the damper assembly be in?
AIR VALVE TYPE AIR CLEANER
DIAPHRAGM SPRING
VACUUM MOTOR,
DIAPHRAGM \
TO EXHAUST
MANIFOLD -
. SHROUD
Figure 5-13
AIR BLEED
VALVE
CLOSED
FULL
VACUUM
SIGNAL TO
VACUUM MOTOR
TO MANIFOLD
VACUUM
2. What is the position of the air

bleed valve below 85°F?
Explain what holds the valve in

this position.
Figure 5-14
30
-------
HOT AIR DELIVERY MODE

DIAPHRAGM SPRING
VACUUM MOTOR
DIAPHRAGM \
Figure 5-15
TEMPERATURE
SENSOR
SPRING
TO
VACUUMS
MOTOR
WEAKENED
VACUUM SIGNAL
TO MANIFOLD
VACUUM
Figure 5-16
REGULATING MODE
DIAPHRAGM SPRING
VACUUM MOTOR
DIAPHRAGM \
3. Explain how the damper assembly is

moved when the engine is started.
Is heated or cold air allowed to

enter the carburetor?
4. Explain how some vacuum is destroyed

between 85-105°F.
5. Explain how the damper assembly is

moved into the regulating mode when

vacuum decreases.
Figure 5-17
31
-------
TEMPERATURE
SENSOR
SPRING
I
A
j
TO MANIFOLD
VACUUM
Figure 5-18
VACUUM MOTOR
DIAPHRAGM \
COLD AIR DELIVERY MODE

DIAPHRAGM SPRING
FILTER
Figure 5-19
DIAPHRAGM SPRING
6. Explain what causes the vacuum to

decrease lower at approximately

130°F.
7. What mode does the damper assembly

move to when vacuum reaches approx-

imately 3-8" Hg in the vacuum

motor?
8. Explain how during acceleration,

the damper assembly is moved into

the cold air delivery mode.
Figure 5-20
32
-------
H. Explain the effect heated air systems can have on HC-CO and drive-

ability.

NOTES:
1. List the advantages of using a heated air system.

b)
HOT AIR DELIVERY MODE

DIAPHRAGM SPRING
VACUUM MOTOR
DIAPHRAGM \
Figure 5-21
TO MANIFOLD VACUU
OPENING
TO
EXHAUST
HEAT
SHROUD
HOT IDLE
'COMPENSATOR
TEMPERATURE
SENSOR
2. Explain the purpose of the vacuum

delay valve shown in Fig. 5-21.

a)
b)
3. Explain the purpose of the hot idle

compensator shown in Fig. 5-22.

a)
b)

d)
Figure 5-22
33
-------
I. Thermostatic Air Cleaner Operational Checks.
1. Figure 5-23 shows a thermostatic
air cleaner. List the basic steps
of the operational check.
a)
THERMOSTATIC AIR CLEANER
Figure 5-23
b)
0
d)
e)
f)
g)
h)
34
-------
2. Fig. 5-24 shows a vacuum motor air

cleaner. List the basic steps of

the operational checks.

a)
b)
VACUUM MOTOR AIR CLEANER
Figure 5-24
c)
d)
If the damper assembly does not

move, list the steps to take to

pinpoint the problem.

4)
Explain what modes the damper

assembly should go through as the

engine warms up.

c)
35
-------
Fill out the following worksheet as you perform the tests
THERMOSTATIC AIR CLEANER WORKSHEET
Engine
Speed
THERMOSTATIC
Off
Idling
Test
Conditions
TYPE
Temperature
Below 80°F
Temperature
Between
100-130°F
Cold Air
Mode

Regulating
Mode

Hot Air
Delivery Mode

If equipped with vacuum
override motor
Snap Accel-
eration
Idling
VACUUM MOTOR
Off
Idling
Idling
Idling
Temperature
Between
100-130°F
Temperature
Above 130°F
TYPE
Check
Position
Temperature
Below 80°F
Temperature
Between
100-120°F
Temperature
Above 130°F

36
-------
STUDENT'S WORKBOOK

Air Injection Systems

Unit 6
Introductory Notes:
A. Identify the main components of the Air Injection System.

1.
Figure 6-1
37
-------
B. Show the flow path of air through the air injection system during

normal operation.
Notes
Figure 6-2

C. Show the operation of the diverter valve.

1. Show the normal flow of air through

the diverter valve during idle, and

cruise conditions.
Figure 6-3
2. Show the air flow through the

diverter valve during deceleration,

a) What is the purpose of the
manifold vacuum sensing line?
b) How long does the "dump" condi-
tion last?
c) What condition does the diverter
valve prevent?
Figure 6-4
38
-------
Notes:
D. Show the flow of air through the diverter valve when excessive pres-

sure builds up in the system.

Notes:
Figure 6-5

E. Explain the operation of the air switching valve.

1. What device controls vacuum to the

air switching valve?
2. Where is all pump air directed at

low coolant temperatures?

3. Above specified coolant temperature

where is pump air directed?
INTAKE
MANIFOLD
VACUUM
AIR SWITCHING VALVE
Figure 6-6
39
-------
F. Show the operation of the air injection system check valve.

1. Show the normal flow of air

through the check valve.
CHECK VALVE
Figure 6-7
2. Explain how the check valve pre-

vents exhaust gases from flowing

back into the system in case of a

belt, pump or hose failure.
Figure 6-8

G. Explain the operation of the "GULP" valve.

s ^ 1. What condition does the gulp valve

prevent?
•0

*
DISTRIBUTION
AIR

ruiwr
•*-- • '—11—'
1 [ — CJ
' i j,
3

CHECK
VALVE
L
SIGNAL LINE
TO
INTAKE
MANIFOLD^
DISCHARGE
TO
GULP VALVE INTAKE MANIFOLD
2. When does the gulp valve operate?

3. Explain how the gulp valve "leans

out" the air/fuel mixture in the

intake manifold.
Figure 6-9
40
-------
4. Where would the relief valve be
located in a system with a gulp
valve?
H. Explain the effect the air injection system can have on HC-CO
emissions and driveability.
1. If the air injection system is dis-
connected how much higher will HC-
CO emissions be?

2. List the conditions that can cause
the air injection system to cause a
rough idle.
a)
b)
c)
3. What condition can occur if the
diverter valve fails to operate on
deceleration?

4. Will disconnecting an air pump show
a significant increase in power or
fuel economy?
Notes:
41
-------
I. Air Injection System Operational Checks

1. Figure 6-10 shows an air pump drive

belt. List the checks that are

necessary on this belt.

a)
b)
Figure 6-10
AIR INLET
FILTER
Figure 6-11
MANIFOLD VACUUM
SIGNAL LINE
2. Figure 6-11 shows the centrifugal

air filter on the air pump. List

the necessary checks for this air

filter.

a)
b)
Figure 6-12
3. List the conditions that should be

checked during a visual inspection

of air and vacuum hoses.

a)
b)
c)
d)
42
-------
VJJ7
TILL
Figure 6-13
4. Figure 6-13 shows an air pump flow

test being performed. List the

basic steps necessary to perform

this test.

a)
b)
c)
d)
Notes:
Figure 6-14
5. Figure 6-14 shows a diverter valve

being tested. List the basic steps

necessary to perform this test.

a)
b)
c)
d)
Notes:
43
-------
Figure 6-15
Figure 6-16
6. A check valve is shown being tested
in Figure 6-15. List the basic
steps necessary to perform this
test.
a)
b)
c)
Notes:
7. Figure 6-17 shows the gulp valve
being tested. List the basic steps
necessary to perform this test.
a)
b)
Figure 6-17
44
-------
Fill out the following worksheet as you perform the checks
AIR INJECTION SYSTEM WORKSHEET
Engine Speed
0
0
0
Idle and
1500 rpm
Idle
2000 rpm
Idle
Idle
Test Condition
AIR PUMP DRIVE BELT
CENTRIFUGAL FILTER
AIR AND VACUUM HOSE CONDITION
PUMP AIR FLOW AT DISCHARGE
HOSE END
DIVERTER VALVE TEST
DIVERTER VALVE DISCHARGE ON
DECELERATION
GULP VALVE TEST
GULP VAVLE TEST
Pass

Fail

45
-------
STUDENT'S WORKBOOK

Fuel Evaporation Control

Unit 7
Introductory Notes:
A. List the main parts of the fuel evaporation control system.

1.
VAPOR SAVER SYSTEM
2.
3.
Figure 7-1
Label each main part listed. 7
Notes:
47
-------
B. Explain the operation of the following fuel evaporation system compo-

nents.

N 1. Fuel tanks and filler necks
Figure 7-2
PRESSURE-VACUUM RELIEF CAP
TANK PRESSURE 1/2 - I PSI
SEALING
GASKET
OUTER SHELL
LOCKING
LIP
2. Fuel tank filler caps - (tank under

pressure)
Figure 7-3

Show the flow path the fuel vapors.

^ 3. Fuel tank filler cap - (tank under

vacuum)
CAP RELIEVING TANK VACUUM

SEALING
GASKET
OUTER SHELL
LOCKING
LIP
Figure 7-4

Show the flow path for fuel vapors,
48
-------
HORIZONTAL MOUNTED LIQUID
\APOR SEPARATOR
TO CHARCOAL
CANISTER
MOUNTING
HOLE''
Figure 7-5
BUILT-IN SEPARATOR
RESTRICTOR
ORIFICE
FUEL VAPOR
FUEL TANK
Figure 7-6
CHARCOAL CANISTER
HOSE
CARBURETOR
OR
AIR CLE
CHARCOAL
GRANULES
4. Liquid-vapor separator

from tank)
- (separate
5. Liquid-vapor separator - (on tank)
6. Charcoal canister
OUTSIDE AIR
Figure 7-7
49
-------
C. Explain the methods used to purge fuel vapors from the charcoal

canister.

1. Variable purge method -
AIR
TANK
-CARBON
CANISTER
Figure 7-8

Show air and purged fuel vapor
path.
a) What causes this purge method
to change or be variable?
b) Explain how the fuel vapors are
removed from the canister.
c) What happens to the air and fuel
vapors after they leave the
canister?
DEMAND
PURGE SYSTEM
FROM
FUEL
TANK
RESTRICTED
ORIFICE
2. Demand purge method -

a) Where does the purge line
connect to the carburetor?
Figure 7-9

Show air and purged fuel vapor
path.
b) Does canister purging occur
during idle or during off-idle
operation?
50
-------
IE
CONSTANT 8 DEMAND
PURGE SYSTEM
3. Constant and demand purge -

a) What system does the constant
purge tie into?
b) What limits the amount of fuel
and air purged from the canis-
ter?
Figure 7-10

Label each part of the system.

D. Explain the operation of carburetor fuel bowl vents.

Notes:
1. Engine shut off or idling,
TO CANISTER
CARBURETOR
THROTTLE
CLOSED
Figure 7-11

Show the fuel vapor path.
51
-------
2. Engine running throttle open -
TO CANBTER
TO CARBURETOR
LMKAGE
CLOSED ANTI
PERC MU.VE
CARBURETOR
BOWL
THROTTLE
OPEN
Figure 7-12

E. Explain the effect the fuel evaporation control system has on HC-CO
emissions and driveability.
1. Explain how poor hose connections
increase HC emissions to atmosphere.
2. Explain how torn or deteriorated
fuel tank filter cap seals increase
HC emissions to atmosphere.
3. Explain why it is necessary to
follow the Vehicle Emissions Con-
trol Label during carburetor
adjustment.
52
-------
Notes:
BOTTOM OF CANISTER
FBERGLAS
FILTER
F. Fuel Evaporation Control System Maintenance Checks

1. List the visual checks that should

be performed on the fuel evapora-

tion control systems.

a)
b)
c)
Figure 7-13
Notes:
Fill out the following worksheet as you perform the tests.
Engine Speed
0
0
0
0
0
0
Test Conditions
VISUAL INSPECTION
Fuel tank filler cap
Fuel tank and hose connection
condition
Liquid vapor separator and/or
check valve condition
Type of purge system
Canister line condition
Filter condition
Pass

Fail

53
-------
STUDENT'S WORKBOOK
Exhaust Gas Recirculation
Unit 8
Introductory Notes:
A. Explain the purpose of the EGR valve.
1. What does the EGR valve control?
2. What happens as the EGR valve opens?
Figure 8-1
Label each part of the system.
3. What opens the EGR valve?
55
-------
B. Identify and explain the components that can be used to control the

EGR valve.

___ 1. Explain the purpose of the Coolant

Temperature Override switch (CTO).
COOLANT
( | TEMPERATURE
_[" OVERRIDE
\ SWITCH
Figure 8-2
a) Where is the CTO switch normally
located?
b) What temperature is sensed by
the CTO switch?
c) Can vacuum pass through the
switch at low coolant
temperatures?
Notes:
EXHAUST BACK-PRESSURE
SENSOR (TRANSDUCER)
Figure 8-3
2. Explain the purpose of the exhaust

back pressure sensor.
a) What pressure is sensed by the
back pressure sensor?
b) Where is the back pressure sensor
normally located in the EGR
system?
c) Does the back pressure sensor
allow vacuum to reach the EGR
valve under low exhaust back
pressure conditions or high ex-
haust back pressure conditions?
56
-------
Figure 8-4
3. Explain the purpose of the vacuum

amplifier.
a) List the two vacuums that enter
the amplifier.
1)

2)
b) What source of vacuum operates
the EGR valve?
c) Where does the venturi vacuum
signal come from?
C. Explain the operation of the ported vacuum EGR system with a CTO

switch.
PORTED VACUUM SYSTEM
LOW COOLANT TEMPERATURE
CARBURETOR

EGR VALVE /
Figure 8-5

Show the vacuum path during
this condition.
1. List the events that occur as the

throttle is opened and coolant

temperature is low.

d)
e) Describe the effect this has on
cold engine driveability.
57
-------
PORTED VACUUM SYSTEM
COOLANT AT
NORMAL OPERATING TEMPERATURE
CARBURETOR
2. List the events that occur as the

throttle is opened and coolant

temperature is normal.

a)
b)
c)
Figure 8-6

Show the vacuum path during
this condition.

Notes:
VENTURI VACUUM EGR SYSTEM
D. Explain the operation of the venturi vacuum EGR system with a CTO

switch.

1. List the events that occur as the

throttle is opened and coolant

temperature is low.

a)
b)
c)
d)
CARBURETOR VACUUM
AMPLIFIER

VENTURI VACUUM LINE-
INTAKE MANIFOLD
VACUUM LINE
EGR VALVE
Figure 8-7

Show the path of the vacuum
during this condition.
58
-------
VENTURI VACUUM EGR SYSTEM
BURETOR VACUUM
AMPLIFIER
VENTURI VACUUM LINEx
INTAKE MANIFOLD
VACUUM LINE
EGR VALVE
Figure 8-8

Show the path of vacuum during
this condition.
2. List the events that occur as the

throttle is opened and coolant

temperature is normal.

a)
b)
c)
d)
E. Explain the operation of the ported vacuum EGR system with the back

pressure sensor.

1. List the events that occur with the
engine at idle or very low speeds.
ENGINE IDLING
BACK PRESSURE
SENSOR FILTER
CTO SWITCH

PORTED VACUUM
EXHAUST GAS

EXHAUST BACK
Figure 8-9

Show the path of vacuum during
this condition.
a)
b)
c)
d)
59
-------
ACCELERATION
TO INTAKE
MANIFOLD
Figure 8-10

Show the path of vacuum during
this condition.
FULL THROTTLE OPERATION
2. List the events that occur during

acceleration.

a)
b)
c)
d)
Figure 8-11
3. List the events that occur during

wide open throttle acceleration.

a)
b)
c)
d)
Notes:
60
-------
F. Explain the effect of the EGR system on HC-CO and NO emissions and
X

driveability.

Notes:
EGR VALVE
NOT
PROPERLY
CLOSED
Figure 8-12
1. List the effects of an EGR valve

that does not close properly.

a)
b)
c)
d)
2. List the conditions that can cause

the EGR valve to open too soon or

not completely close.

e)
61
-------
Notes:
Figure 8-13
3. Explain what happens if the EGR
valve base gasket leaks.
Explain what can happen with a CTO
switch failure.
a)
b)
Des'cribe the importance of Figure
8-13.
62
-------
G. EGR System Operational Checks.
Figure 8-14
1. Figure 8-14 shows an EGR valve

being tested. List the basic steps

necessary to perform this test.

d)
Notes:
63
-------
PORTED VACUUM SYSTEM
LOW COOLANT TEMPERATURE
CARBURETOR
/
2. Figures 8-15 and 8-16 show a ported

vacuum and venturi vacuum EGR sys-

tem. List the basic steps neces-

sary to operationally test these

systems with coolant temperature

below 80°F.

a)
Figure 8-15

Show the path of vacuum during
these conditions.
b)
VENTURI VACUUM EGR SYSTEM
EGR VALVE
VENTURI VACUUM LINE
VACUUM
AMPLIFIER
INTAKE MANIFOLD
VACUUM LINE
Figure 8-16
Notes:
0
c)
64
-------
PORTED VACUUM SYSTEM
COOLANT AT
NORMAL OPERATING TEMPERATURE
CARBURETOR
E6R
CTO
SWITCH
3. List the basic steps necessary to

perform an operational test on the

systems shown in Figures 8-17 and

8-18 when the engine is at operat-

ing temperature.
Figure 8-17

Show the path of vacuum during
these conditions.
VENTURI VACUUM EGR SYSTEM
VENTURI VACUUM LINE\ >
VACUUM
AMPLIFIER
NNTAKE MANIFOLD
VACUUM LINE
EGR VALVE
Figure 8-18
ENGINE IDLING

BACK PRESSURE
EXHAUST BACK
PRESSURE // PORTED VACUUM
SENSING T
SWITCH
Figure 8-19
4. Figure 8-19 shows a ported vacuum

EGR system with an exhaust back

pressure sensor. List the basic

steps necessary to operationally

test this system with coolant

temperature below 80°F and at

normal operating temperature.

a)
65
-------
Notes:
b)
c)
d)
e)
f)
66
-------
Fill out the following worksheet as you perform the tests.
Engine
Speed
Idle
2000
rpm
2000
rpm
2000
rpm
2000
rpm
Test
Conditions
EGR VALVE OPERATIONAL CHECK

Ported Vacuum or Venturi Vacuum
EGR Systems
Engine Cold
Check EGR valve stem movement or
vacuum to EGR valve
Engine Warm
Check EGR valve stem movement or
vacuum to EGR valve
Ported Vacuum EGR System with
Back Pressure Sensor
Engine Cold
Check for valve stem movement or
vacuum to EGR valve
Engine Warm
Check EGR valve stem movement or
or vacuum to EGR valve
Pass

Fail

Vacuum
Reading

67
-------
STUDENT'S WORKBOOK

Spark Control Systems

Unit 9
Introductory Notes:
A. Explain the purpose for retarded timing at idle,

a)
Figure 9-1
b)
c)
d)
e)
69
-------
B. Identify the parts of a typical transmission controlled spark system.

^••^^^^^^^"^•^^^"•^^•^•^^^^^^^^••^^^•^^^^^^^^•^^^
1.
Figure 9-2

Label each main part listed.

C. Explain the operation of the transmission controlled spark system.

1. Transmission in lower gears

a)
SOLENOID VACUUM
DISTRIBUTOR
VACUUM
ADVANCE UNIT
CARBURETOR
IGNITION
Figure 9-3

Show the vacuum path during
this condition.
b)
c)
d)
70
-------
TRANSMISSION
SWITCH
SOLENOID VACUUM
SWITCH

ISTRIBUTOR
VACUUM
ADVANCE UNIT
IGNITION
2. Transmission in high gear,

a)
b)
c)
Figure 9-4

Show the vacuum path during
this condition.

Notes:
d)
71
-------
D. Explain the operation of a transmission controlled spark system with

a coolant temperature override (CTO) switch.

Notes:
0»-I60»F
TO IGNITION
SWITCH
OPEN OVER
35 MPH
OR HIGH GEARS
Figure 9-5

Show the vacuum path during
this condition.
TO IGNITION
SWITCH
OPEN OVER
35 MPH
OR HIGH GEARS
Figure 9-6

Show the vacuum path during
this condition.
1. Coolant temperature below approxi-

mately 160°F.

a)
b)
c)
d)
2. Coolant temperature above approxi-

mately 160°F.

a)
b)
c)
72
-------
E. Explain the operation of a transmission controlled spark system with

HOT and COLD coolant temperature override (CTO) switch.

1. Coolant temperature above approxi-

mately 160°F.

a)
BELOW 225°F-ABOVE I60°F
PORTED
VACUUM
-CTO
HOT OVERRIDE
PORTED
VACUUM
Figure 9-7

Show the vacuum path during
this condition.
ABOVE 225°F
PORTED
VACUUM
-CTO
HOT OVERRIDE
MANIFOLD
VACUUM
Figure 9-8

Show the vacuum path during
this condition.
b)
c)
2. Coolant temperature above approxi-

mately 225°F.

a)
b)
c)
d)
e)
73
-------
F. Explain the operation of the spark delay valve

... 1.
PORTED
VACUUM
TO
DISTRIBUTOR
Figure 9-9
G. Explain the operation of the OSAC valve.

1. What do the letters OSAC stand for?
TO
DISTRIBUTOR
PORTED
VACUUM
OSAC
VALVE
Figure 9-10
a)
b)
c)
d)
e)
74
-------
H. Explain how spark control systems can affect HC, CO, NO and drive-
X

ability.

1. Over advancing spark timing.

a)
b)
c)
2. Failure of transmission controlled

spark system.

a)
b)
3. Failure of CTO switch (hot or cold)

a)
b)
4. Improper spark delay valve or OSAC

valve operation.

a)
b)
75
-------
I. Spark Control Systems Operational Checks.

1. Figure 9-11 shows an operational

_ test on a vehicle with automatic

transmission. List the basic steps

necessary to perform this test.

c)
Figure 9-11
e)
f)
.C
0 VACUUM
•}2ND GEAR
1ST GEAR
PORTED VACUUM
3RD GEAR
Figure 9-12
2. Figure 9-12 shows an operational

test on a vehicle with a standard

transmission. List the basic steps

necessary to perform this test.

d)
76
-------
Figure 9-13
Figure 9-14
TESTING SPARK DELAY VALVE
TESTING SPARK DELAY VALVE
Figure 9-15
3. Figure 9-13 shows an operational

test on a vehicle with a speed

controlled spark system. List the

basic steps necessary to perform

this test.

4. Figures 9-14 and 9-15 show a spark

delay valve being tested. List the

basic steps necessary to perform

this test.

77
-------
Notes:
Figure 9-16
5. Figure 9-16 shows an OSAC valve

being tested. List the basic steps

necessary to perform this test.

a)
b)
c)
d)
e)
Fill out the following worksheet as you perform the checks.
78
-------
SPARK CONTROL SYSTEM WORKSHEET
Engine
Speed
Test Conditions
TRANSMISSION CONTROLLED SPARK (AUTOMATIC)
Approxi-
mately
1500 rpm
Engine at operating temperature
Transmission selector in reverse
TRANSMISSION CONTROLLED SPARK (STANDARD)
Approxi-
mately
1500 rpm
Engine at operating temperature
1st gear (clutch depressed)
2nd gear (clutch depressed)
3rd or high gear (clutch depressed)
SPEED CONTROLLED SPARK SYSTEM
Slowly
increase
to 40
mph
Engine at operating temperature
Rear wheels raised/ jack stands
Increase speed to approximately
40 mph
SPARK DELAY VALVE
Approxi-
mately
1500-
2000 rpm
or use
hand
pump

OSAC VALVE
1500-
2000 rpm
throttle
closed
Engine at operating temperature.

Pass

Fail

Vacuum
Readings

79
-------
STUDENT'S WORKBOOK

Catalytic Converter Systems

Unit 10
Introductory Notes:
A. Explain the purpose of the catalytic converter.

1. List the functions of the catalytic

converter.

a)
MUFFLER
Figure 10-1
b)
O
d)
81
-------
B. Explain the construction of monolith and pellet type converters

1. Monolith converters

a)
MONOLITH CONVERTER
EXHAUST
GASES
HONEYCOMB
MONOLITH
STAINLESS STEEL
SHELL
STAINLESS
STEEL MESH
Figure 10-2
Label the components and show
the flow path.
EXHAUST GAS FLOW-THRU
PELLET-STYLE CATALYTIC
CONVERTER
INSULATION
EXHAUST
GASES
Figure 10-3

Label the components and show
the flow path.

Notes:
b)
c)
d)
2. Pellet type converters

a)
b)
c)
d)
82
-------
C. Explain how engine operation affects catalytic converter operation,

1.
ADDITIONAL AIR IS SUPPLIED TO
THE CATALYTIC CONVERTER BY'
a)
b)
Figure 10-4
Notes:
D. Explain the purpose of catalytic converter protection systems,

1.
EXCESSIVELY RICH MIXTURES
CAN LEAD TO A DESTROYED
CATALYTIC CONVERTER
3.
Figure 10-5
a)

c)
4.
83
-------
E. Explain the operation of a catalytic converter protection system.

Notes:
THERMACTOR
WITH TVS
SWITCH AND
VACUUM DELAY
VALVE
EGR VALVE AIR CLEANER
TVS SWITCH
BELOW
60° F
BYPASS
VALVE
AIR \
PUMP
TO SPARK
PORT
COLD
ENGINE
OPERATION
Figure 10-6

Show the vacuum path and AIR
pump flow path.
THERMACTOR
WITH TVS
SWITCH AND
VACUUM DELAY
VALVE
EGR VALVE AIR CLEANER
TVS SWITCH
ABOVE
60° F
BYPASS
VALVE
CHECK
VALVE
AIR \
PUMP
TO SPARK
PORT
WARM
ENGINE
OPERATION
Figure 10-7
Show the vacuum path and AIR
pump flow path.
1. Protection system operation when

the engine is cold.

d)
2. Protection system operation at

normal operating temperature.

d)
84
-------
THERMACTOR
WITH TVS
SWITCH AND
VACUUM DELAY
VALVE
EGR VALVE
BYPASS
VALVE
CHECK
VALVE
AIR \
PUMP
OPERATION DURING
EXTENDED IDLE
OR EXTENDED
DECELERATION
Figure 10-8

Show the vacuum path and AIR
pump flow path

Notes:
j. Protection system operation during

extended idle or extended decelera-

tion.

a)
b)
c)
d)
F. Explain the purpose of exhaust system heat shields,
^^™^^^^^^^^^™~™ -^^^^^^^^^^™ _^
1.
HEAT SHIELDS
INTERIOR
INSULATING
PADS.
CATALYTIC
CONVERTER
HEAT
SHIELDS
LOWER SHIELD
Figure 10-9
85
-------
G. Explain why unleaded fuel must be used in catalytic converter

equipped cars.

1.
LEADED FUEL DESTROYS
CATALYST EFFECTIVENESS
a)
b)
Figure 10-10
H. Explain how catalytic converters can affect HC, CO and NO emissions

and driveability.

1.
2.
4
86
-------
I. List the basic steps for operationally checking a catalytic converter.

Notes:
Notes:
1. Visual Inspection

c)
2. Operational Checks

d)
Fill out the following worksheet as you perform the tests,
87
-------
Engine
Speed
0
Idle
2000
rpm
Test
Conditions
VISUAL INSPECTION
a) Catalytic Converter (s)
b) AIR Pump
c) Protection Systems
d) Hose Condition
e) Hose Connections
f) Hose Routing
OPERATIONAL CHECKS
Tailpipe Analyzer Reading
Tailpipe Analyzer
Reading
Pass

Fail

HC
(PPM)

CO
(%)

88
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-450/3-77-035
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
Student's Workbook for Vehicle Emissions Control
Training
5. REPORT DATE
November 1977
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
B.D. Hayes
M.T. Maness
8. PERFORMING ORGANIZATION REPORT NO
R. A... Ragazzi
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Department of Industrial Sciences
Colorado State University
Fort Collins, Colorado 80523
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.

T900621-01-0
12. SPONSORING AGENCY NAME AND ADDRESS
Control Programs Development Bivision
Office of Air Quality Planning and Standards
Office of Air and Waste Management
U.S. Environmental Protection Agency
13. TYPE OF REPORT AND PERIOD COVERED
Final Report .
14. SPONSORING AGENCY CODE

EPA 200/04
is. SUPPLEMENTARY NOTES Research Triangle Park, N.C. 27711
16. ABSTRACT

It is the intent of this book to explain each basic emissions control system and
some of the more common devices found on today's car. Since it is a student's
workbook it is designed to allow the student to proceed through the key points of
each emissions control system.

Each basic emissions control system presented has the following information pro-
vided:

Part Identification
System Operation
System Control
System Effects on HC-CO and Driveability
Worksheets
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COS AT I Field/Group
Hydrocarbons
Carbon Monoxide
Oxides of Nitrogen
Infrared Exhaust Gas
Analyzer
Ignition
Carburetion
Positive Crankcase
Ventilation
Thermostatic Air
Cleaners
Air Injection Systems
Fuel Evaporation Con-
trol
13. DISTRIBUTION STATEMENT

Release Unlimited
19. SECURITY CLASS (ThisReport)

Unclassified^
21. NO. OF PAGES

Qfi
20. SECURITY CLASS (Thispage)

Unclassified
22.-PRICE
EPA Form 2220.1 (9-73) «U.S. GOVERNMENT PRINTINGOFRCE: 197 8-74 5 - 22M.
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