79-11
Evaluation of Applicability of Inspection/Maintenance
Tests on a Dodge Aspen Prototype
August 1979
by
Thomas J. Penninga
Technology Assessment and Evaluation Branch
Emission Control Technology Division
Office of Air, Noise and Radiation
U.S. Environmental Protection Agency
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Abstract
This report presents testing results which were gathered to determine
the suitability of existing I/M testing scenarios on a Chrysler car with
a computer based emission control system. This car had a microprocessor
based three-way catalyst control as well as computerized spark control.
After suitable baselines were established, various components were made
inoperative in the emission control system. Complete FTP, HFET, New
York City Cycles, and I/M tests were run for each vehicle condition.
This report presents the measured data taken during the tests.
Background
It is anticipated that, in the near future, electronics and computers
will control many of the vital functions of automotive operation now
regulated by mechanical means. As the Inspection/Maintenance effort is
expanded it is a prerequisite that the test procedure used by the
Inspection/Maintenance program be capable of determining equipment
failure and parameter misadjustraent. With the advent of advanced elec-
tronics into automobiles, it is necessary to evaluate the suitability of
existing and proposed I/M tests to these future automobiles. To accom-
plish this evaluation, several prototype cars containing the best pro-
jected electronics of the future will be tested according to both the
Federal Test Procedures and I/M tests. The derived data should indicate
which I/M test best suite these automobiles. This report presents the
data collected on the second such automobile tested by the EPA, a 1979
Dodge Aspen with an EFC and ESC microprocessor controlled emission
control system.
History .
The Aspen was a late 1979 certification vehicle which was delivered to
MVEL for I/M testing on March 20, 1979. Three baseline sets of data
were run. The vehicle was shipped to Gulf Research Laboratory on
March 29, J.979 where it underwent ambient emission testing. On
June 8, 1979 the vehicle was delivered to MVEL.
The I/M testing began on June 29, 1979. After two baseline sequences
were run, the vehicle was tested with five different system deacti-
vations. A final confirmatory baseline sequence was then run.
Testing Procedure
In order to test the vehicle, the following test scenario was used:
a. Federal Test Procedure (FTP) 1979 procedure, non-evaporative,
no heat build.
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b. Raw HC/CO measurement, hood closed, fan off, idle-neutral.
c. Highway Fuel Economy Test (HFET) immediately after FTP.
d. Raw HC/CO measurement, hood closed, fan off, idle-neutral.
e. New York City Cycle (NYCC) immediately after HFET.
f. Raw HC/CO measurement, hood closed, fan off, idle-neutral.
g. Federal Three Mode. The dynamometer was set at 1750 Ibs.
inertia and horsepower was set at 6.4 hp at 25 mph and 13.7 hp
at 52.0 mph. The hood was open and the auxiliary cooling fan
turned on. Idle HC and CO measurements were taken in drive
and in neutral on a garage type analyzer.
h. Loaded Two Mode. The dynamometer was set at 17.3 IHP at 30
mph with the I.W. = 1750 Ibs. The hood was open and the
auxiliary cooling fan turned on. Idle HC and CO measurements
were then taken in neutral.
i. Two Speed Idle Test with raw HC/CO garage type analyzer tested
at 2500 rpm (neutral) and idle (neutral). The hood was closed
and the auxiliary cooling fan turned off.
j. Abbreviated I/M Cycle with raw HC/CO garage analyzer tested at
idle (neutral momentarily accelerated to 2500 rpm (neutral),
and then tested again at idle (neutral). The hood was closed
and the auxiliary cooling fan turned off.
k. Federal Three Mode (same as above).
1. Loaded Two Mode (same as above).
m. Two Speed Idle Test (same as above).
n. ' Abbreviated I/M Cycle (same as above).
o. Prolonged Idle Cycle. With the cooling fan off and hood
closed, idle (neutral) HC and CO measurements were taken every
minute for 10 minutes on a garage type analyzer.
A work sheet recording the I/M test results is shown in
Attachment 1.
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Vehicle Description
The Dodge Aspen supplied by Chrysler for this testing was not a pro-
duction vehicle but a 4000 mile emission-data-vehicle. Attachment 2
lists specific vehicle parameters. The most important aspect of this
automobile's emission control system were the sensors, actuators, and
microprocessor units. A complete description of these components is
given in Attachment 3.
Baseline Data
To accurately determine the effect of the various vehicle conditions it
was necessary to have an accurate baseline determined for each con-
stitutent in each mode in every test type. Confirmatory baseline tests
were run at the end of the test program. This baseline data is dis-
played with the configuration data.
Test Configurations
After the baseline testing and sorting out of the testing procedures
several components of the emission control system were, one by one,
deactivated prior to vehicle testing.
a. EGR Sensor Disconnected - Test Numbers 79-8152 and 79-8153 was
done with the exhaust gas oxygen (EGO) sensor disconnected.
This unit supplies a voltage signal to the FBC computer based
on the oxygen content of the exhaust stream. By disconnecting
the sensor the output voltage goes to zero and the closed loop
system is deactivated. These tests are designated EGO Sensor
disconnected.
b. Coolant Temperature Switch Disconnected - Test Numbers 79-8154
and 79-8155 were run with the Coolant Temperature Switch
disconnected. Because the EGO sensor does not perform pro-
perly until it reaches temperature, the coolant sensor informs
the FCC to operate in open-loop mode until EGO sensor tempera-
, ture is reached.
3. Solenoid Actuated Vacuum Regulatory Disconnected - Test Num-
bers 79-8156 and 79-8157 were run with the solenoid actuated
Vacuum Regulator disconnected. This device connects the
electrical signal from the FCC to a vacuum signal to control
the carburetor in maintaining the A/F ratio at stoichiometric.
Disconnecting the solenoid forces the system to run in a full
rich condition.
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d. Air Pump 100% Bypassed - Test Numbers 79-8158 and 79-8159 were
run with the air pump diverted to atmosphere and both upstream
and downstream air injection lines plugged. This air injec-
tion oxidizes HC and CO at the exhaust port during warm-up and
at the oxidation catalyst during regular operation.
e. EGR Valve Disconnected - Test Numbers 79-8160 and 79-8161 were
run with Exhaust Gas Recirculation (EGR) valve line discon-
nected and plugged. This device recirculates exhaust gas into
the inlet manifold which reduces combustion temperature there-
by reducing NOx formation.
f. Solenoid Actuated Vacuum Regulator - Full Lean - Additional
tests were attempted with the solinoid wired to 12 volt DC.
This condition would result in driving the FCC to a full lean
condition. Because the vehicle stalled over 15 times in the
preconditioning LA-4, this testing mode was terminated.
Test Results
The test results are given in several attachments.
a. The FTP, HWFET, and NYCC with the corresponding raw HC/CO
readings are given for baseline configuration studies in
Attachment 4. The HC, CO, CO and NOx readings are in
gms/mile while the fuel economy is in miles per gallon. The
raw HC readings are in ppm Hexane and the raw CO readings are
in percent.
b. Attachment 5 presents the standard I/M test data.
test was run twice, two sets of values are given.
As each
c. Attachment 5 also presents the Prolonged Idle Cycle Data.
List of Attachments
Attachment 1
Attachment 2
Attachment 3
'Attachment 4
Attachment 5
Attachment 6
I/M Test Result Work Sheet
Test Vehicle Description
Chrysler FCC and ESC Description
Dilute and I/M Sample Data
I/M Sample Data
I/M Prolonged Idle Test Data
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• /•'.:' ro;•.-.!• vr-.;- T ;.;:.-.••;.,..<•.: ].'W ].: i.-i-sf. HC, CO T>.-:il;: Sheet
'i c:i:!>n J •:.! .:\>'1.'.•: ^ Location.: UrH.o :
Vehicle: n;>5jc.!.ine. Other:
Attachment 1
CO
CO!'
• Hood closed, fan oTf
Xran :;r.ii 5; K i.on-n e ' ; t rn \
AFTER HWFF/f
Ilood clo?ecl, • fan off
Traus ID if. s ion-nt'.u t r a 1
AFTP.R NYCH
HooiJ closed, fan off
FEDERAL 3 MODE jr. UJ.-
Hooc.1 open, fan on
Set; 13.7 on thunihwb(;al
52 ni'H-mrix 3 min.
Set 6.4 IMP '51 25 MTU
^^7.itll I'cuiuent
25 Ml'Il-raax 3 nin.
Iflle (Drive)
Idle (Neutral)
LOADED 2 MODF. X.uJ . = I
Hood open, fan en
Set dyno at f 7. 3
l or
on Pendent ac 30 -MPH
30 MPH
Idle (Neutral)
TWO SPI:ED IDLE CYCLE
Hood closed, fan off
Idle (Neutral)
Increase Idle spoed to 2500
+ 100 1-PM
Idle (HouLi-al)
f . '
A^RllEVlATril I/M 1}^}:. CYCLE
Hood clonocl, fan off
Idle GO
?'o:'iontr.ry rev. to 2.100 RPM
Idle (M)
-------
lie:
CO
CO-IT1'NTS
ur "~~'TI ra.'EiiAL iruEE *;om; jr.u1. -
Hood open, f;m on
Sot ''). 7 on Thniiil'n/iJ'jo.l.
52 Mi'!!- "/ax 3 niin.
Sst 6..'} IUPC25 MPii
u it'll PondcMit
25 Ml'H-Max 3 rcin.
Idle (Hrive)
Idle (Neutral)
RI:PEAT LOADED T'.JO MODE x.ux -175-0i
Hood open, fan on
Set 'Jy.>o nr 17.3
or
on Pendent at 30 TTH
30 MPII
Idle (Keutral)
REPEAT TWO SPEED IDLE CYCLE
Eood closed, fan off
Idle (Neutral)
Incrr-.asc Idle Speed to
2500 + 100 KPM
Idle (Neutral)
}V'~"V. ABBREVIATED I/M CYCLE
Hood closed, fan off
Idle (Neutral)
Momentary rev. to 2500 RPM
Idle (Neutral)
PROLONGED IDLE CYCLE
Hood closed, fan off
Idle (Neutral) Minutes
0
1
2
3
<4
5
6
7
8
9
10
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Attachment 2
Test Vehicle Description
Model Year
Make
Emission Control System
Engine Type
Bore x Stroke
Displacement
Rated Horsepower
Transmission
Axle Ratio
Chassis Type
Tire Size
Inertia Weight
VIN
AHP
40% Fuel Tank Volume
1979
Dodge Aspen
EGR, AI, OC, 3-Way, Closed Loop
Otto Spark
3.40 x 4.12 inches
225 CID
101 hp
A-3
2.94
Sedan
D78xl4
3500 Ibs.
B103
13.5
7.20
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Clinics
Service & Parts Division
(TVQ
SERVICE
Of lnt«**t 3 General Manager D Sales Manager D Service-Manager D Parts Manager CD Service Technicians
A new concept in controlling exhaust emissions has
been incorporated in production.
The new system is called the Electronic Feedback
Carburetor Concept. A unique feature is the use
of the Electronic Spark Control for the first time
on six-cylinder engines. Both systems work together
as the combustion computer controlling ignition
timing and air-fuel ratios in the carburetor. The
precise control of air-fuel ratio has permitted a
three-way catalyst to be used in this system to.
simultaneously reduce all three major exhaust
pollutants; hydrocarbons, carbon monoxide, and
oxides of nitrogens.
The attached information provides a complete detailed
description of the system, diagnosis, and service
procedures. Testing procedures and specifications
for the Electronic Spark Control portion are out-
lined in the 1979 Service Manual.
POLICY: Information Only
J. W. Farley C/
Manager - Service Planning
Models
1979 Volare/As]
Equipped With
225-1BBL and
California
Emissions
Package
Subject
Electronic
Feedback
Carburetor (EF»
Index •
FUEL
Date:
April 30, 1979
No. 14-05-79
P-2518-C
CHRYSLER
CORPORATION
(THIS BULLETIN IS SUPPLIED AS
TECHNICAL INFORMATION ONLY
AND IS NOT AN AUTHORIZATION
. FOR REPAIRS) REPRINT OF THIS
MATERIAL NOT AUTHORIZED
UNLESS APPROVED.
niRYS!.i;K Dodge
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No. 14-05-79
- 1 -
FEEDBACK
CARBURETOR
CONTROLLER
FEEDBACK
CARBURETOR
OXYGEN
SENSOR
REGULATOR
VALVE
MANIFOLD
VACUUM
ELECTRONIC FEEDBACK CARBURETOR CONCEPT
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14-05-79 - 2 -
ELECTRONIC FEEDBACK CARBURETOR
(EFC) SYSTEM '.
The EFC system is essentially an emissions control system
(Figure 1) which utilizes an electronic signal generated
by an exhaust gas oxygen sensor to control, precisely, the
carburetor air-fuel mixture ratio. This in turn allows the
engine to produce exhaust gases of the proper composition
to permit the use of a three-way catalyst, a device which
can convert all three types of pollutants -- hydrocarbons (EC),
carbon monoxide (CO), and oxides of nitrogen (NOx) — into
harmless substances.
SYSTEM COMPONENTS AND DESCRIPTION
The major components of the EFC system are as follows:
o Dual Catalytic Converters
Oxidation catalyst
3-way catalyst
o Oxygen Sensor
o Mileage Counter
o Combustion Computer
o Feedback Carburetor
o Solenoid-Operated Vacuum Regulator Valve
Dual Catalytic Converters
Catalytic converters are devices which decrease HC and CO
emissions, or NOx emissions, or all three of these exhaust
pollutants. They are muffler-like in appearance and are
mounted on the underside of a vehicle as part of the exhaust
system. Two converters, mounted in tandem, are used with the
EFC system (Figure 2).
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No. 14-05-79
- 3 -
OXIDATION
CATALYST
THREE-WAY
CATALYST
MUFFLER
CATALYTIC CONVERTERS
Oxidation Catalyst: The oxidizing catalytic converter
contains a platinum-coated, ceramic, honeycombed structure.
Through a complex chemical reaction, the platinum stimulates
the oxidation (burning) of hydrocarbons and carbon monoxide
and converts them to harmless carbon dioxide and water vapor.
Effective operation of this type of catalyst requires temper-
atures of 600°F (315°C) or higher as well as an adequate supply
of oxygen in the exhaust gas. Oxidation catalysts in current
use will normally "light off" (start oxidizing) within two
minutes after the first start of a cold engine.
Three-way Catalyst; Research scientists and catalyst supplier
companies determined that by adding rhodium, a rare and costly
"noble" metal, the oxidizing converter could also "reduce",
or separate, oxides of nitrogen into nitrogen and oxygen,
basic components of pure air. This reducing action provides
inherently better exhaust emissions control that was obtainable
using only exhaust gas reci'rculation, an oxidation catalyst.
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No. 14-05-79
- 4 -
or engine modification techniques. Its use also allows
richer air-fuel mixtures, more spark advance, and less
'•xhaust gas recirculation — which collectively improve
both drivcability and fuel economy.
Effective catalytic control of all three pollutants is
possible when the correct balance of excess CO is reached
icr reduction and excess oxygen is reached for oxidation.
It is necessary, therefore, to maintain precise control of
the air-fuel mixture entering the engine, keeping it very
close to the stoichiometric level (chemically correct for
theoretically complete combustion).
Figure 3 shows the characteristics of a three-way catalyst.
The curve of efficiency as a function of air-fuel indicates
that when the air-fuel ratio is lean (excess of oxygen),
the control of HC and CO is very good, but control of NOx
is poor. On the other hand, when the air-fuel mixture is
rich (deficiency of oxygen), the control of NOx is very good
but control of HC and CO is poor. At the chemically correct
mixture, a narrow window exists where the control of all
three pollutants is quite good. Maintaining the exhaust
constituents at this precise value at which the three-way
catalyst is most effective is the purpose of the EFC closed
loop system.
100-1
13:1
14:1 15:1
AIR — FUEL RATIO
16:1
CHARACTERISTIC CONVERSION EFFICIENCIES
THREE-WAY CATALYST
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No. 14-05-79
- 5 -
A downstream oxidation catalyst with oxygen supplied by an
air pump is used to clean up the remaining HC and CO left
after the exhaust gases have passed through the three-way
catalytic converter.
Oxygen Sensor
If the air-fuel mixture is just a fraction above or below
the ideal ratio, the composition of exhaust by-products
will be altered, impairing the efficiency of the three-way
catalyst. To provide the EFC system with an indication of
the exhaust gas composition, an oxygen sensor (Figure 4)
is threaded into the exhaust manifold where it is directly
in the exhaust gas stream.
The sensor is a sophisticated device supersensitive to the
presence of oxygen. This sensitivity to oxygen is crucial.
With an oxygen deficiency in the exhaust gas, outside oxygen
diffuses through the sensor, acting as an electrolyte and
generating a voltage.
ZIRCONUM
DIOXIDE BODY
PROTECTING SHIELD
SHELL
INTERNAL AND EXTERNAL
SURFACES PLATINUM PLATED
HOUSING
OXYGEN SENSOR
The oxygen sensor is essentially a galvanic battery consisting
of a cylindrical electrolyte element of zirconium dioxide which
is coated inside and out with platinum. The outer platinum
electrode is exposed to the hot exhaust gases while the inner
platinum electrode is exposed to the atmosphere (Figure 5).
A porous ceramic (spinel) coating protects the fragile
platinum against damage.
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No. 14-05-79
6 ~
GASTIGHT ELECTRICALLY
CONDUCTIVE SEAL
AIR
EXHAUST
GASES
HOUSING
ZIRCONIUM DIOXIDE
ELECTROLYTE
SPINEL
COATING
PLATINUM
INNER ELECTRODE
PLATINUM
OUTER ELECTRODE
OXYGEN SENSOR ELEMENT — SCHEMATIC
900-
800-
700-
600-
I 500-
LU
CD
400-
o
> 300-
200-
100-
0
13:1
LEAN)
V
14:1
15:1
16:1
AIR — FUEL RATIO
CHARACTERISTIC OXYGEN SENSOR
OUTPUT VOLTAGE CURVE
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No. 14-05-79
- 7 -
When heated to operating temperature by the hot exhaust
gases, the sensor will generate a voltage. When the oxygen
content is high (lean mixture), it puts out a low voltage.
When the oxygen content is low (rich mixture), the voltage
output is high (Figure 6). This relationship between available
oxygen and sensor output voltage causes the sensor to function
as a rich-lean switch. The sensor output voltage is used by
the Feedback Carburetor Controller to calculate and adjust the
air-fuel mixture as needed for optimum catalytic converter
efficiency.
The sensor's internal impedance, output voltage, and time
response are all functions of temperature. This temperature-
dependency is .an important consideration during cold starts
and other low-temperature operating modes.
In addition to the spinel coating which protects the sensor's
platinum-coated outer electrode from exhaust gas erosion, a
metal shield, louvered to admit exhaust gases, protects the
fragile zirconium dioxide body from abrasion by exhaust parti-
culates and from breakage during handling.
In order to ensure good air-fuel ratio control over the life
of the vehicle, the sensor must be changed at 15,000* mile
(24 000 km) intervals.
15,000 MILE
REMINDER LIGHT
SPEEDOMETER - ODOME7
RUBBER SHIELD
SPEEDOMETER
CABLE
MILEAGE COUNTER
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No. 14-05-79
~ 8
'•'. 11 o gc«; Cou r. t e r
A mileage counter (Figure 7) in-line with the speedometer is
used to'indicate when to replace the oxygen sensor. When
lo.OOO .r.iles (24 000 km) have elapsed, the counter will actuate
an' "EFc' SYSTEM" instrument panel light. The counter can be
reset at the time the sensor is replaced.
ELECTRONIC
SPARK CONTROL
COMPUTER
HOUSING
FEEDBACK
CARaU.RETOR
COrJTROLLER
COMBUSTION COMPUTER
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No. 14-05-79 ~ 9
Combustion Computer with Feedback Carburetor Controller
The Combustion Computer on the air cleaner houses both
the Electronic Spark Control Computer and the Feedback Carbu-
retor Controller (Figure 8).
The electronic spark control computer interfaces with the
feedback carburetor controller and provides optimum engine
ignition timing through electronic control of the spark advance.
The feedback carburetor controller is the information processing
component of the EFC system. It monitors the voltage generated
by the oxygen sensor and receives input signals from sensors
reporting engine coolant temperature, manifold vacuum, engine
rpm, and engine starting. The controller interprets the various
inputs and then transmits the proper output signal to the
solenoid-operated vacuum regulator valve, which in turn forwards
a signal to the carburetor.
Feedback Carburetor
A single barrel feedback carburetor is used to maintain the
air-fuel ratio within the limits required for efficient catalysis
in the three-way catalyst. The vacuum signal acts simultaneously
on two diaphragms (Figure 9), one for controlling the idle system
and the other for controlling the main metering system. The
diaphragms control tapered rods which vary the size of orifices
to adjust the idle system air bleed and the main metering system
fuel flow. These variable controls complement and are used in
parallel with a fixed idle air bleed and main fuel metering jet.
A "lean" command from the Feedback Carburetor Controller to the
vacuum regulator will result in an increasing vacuum level to
the carburetor. This will cause the diaphragm to move the idle
air bleed rod upward in its orifice causing increased idle air
bleed. Simultaneously, the other diaphragm will move the main
metering rod upward in its orifice causing reduced fuel flow.
The result from both circuits is a leaner air-to-fuel ratio.
On the other hand, a "rich" command will result in a lower
vacuum level to the carburetor which will cause the spring-
loaded rods to move in the opposite direction and furnish a
richer mixture. The range of mixture control is approximately
4 air-to-fuel ratios, 2 rich and 2 lean, or 14.7 (± 2.0) to 1.
The carburetor is calibrated so that the desired nominal flow
is obtained with a vacuum signal of 2.5 inches Hg (8.5 kPa).
Other features of the feedback carburetor include
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No. 14-05-79
- 10 -
o A throttle-actuated wide-open-throttle enrichment
valve (not shown)
o An idle mixture screw, concealed within the throttle
body to prevent tampering
o A separate nipple on the throttle body to serve
as a source for the air pump diverter valve vacuum
signal.
FIXED IDLE
AIR BLEED
FEEDBACK CONTROLLED
IDLE AIR BLEED
VACUUM CHANNEL
FUEL BOWL
FEEDBACK CONTROLLED
MAIN SYSTEM FUEL
RESTRICTOR
, CONCEALED
IDLE ADJUSTMENT SCREW
MAIN
METERING JET
FEEDBACK CARBURETOR
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No. 14-05-79
~ 11
VENT PORT
ARMATURE
RETURN SPRING
VENT
r SOLENOID
^ OUTPUT
TO CARBURETOR
VACUUM INPUT
(MANIFOLD VACUUM)
REGULATED
VACUUM
, VACUUM
REGULATOR
SOLENOID-VACUUM REGULATOR VALVE
Solenoid-Operated Vacuum Regulator Valve
A solenoid-operated vacuum regulator valve (Figure 10) con-
verts the electrical signal from the Feedback Carburetor
Controller to a vacuum signal to control the carburetor in
maintaining the air-fuel ratio at stoichiometric (14.7:1).
Intake manifold vacuum is supplied to the regulator at the
lower port, and a regulated 5 inches of mercury (Kg)(17 kPa)
is generated within the device. The armature in the electric
solenoid at the top of the unit is fitted with a conical tip
at each end and functions as a valve. When there is no
electrical signal to the solenoid, the spring-loaded armature
is held downward as shown to block off the port to the regulated
vacuum and open the vent port to atmosphere. When the solenoid
is energized, the armature rises off its seat allowing the
regulated vacuum signal to pass to the carburetor while simul-
taneously closing the vent port. The carburetor.control vacuum
signal can be regulated between 0 and 5 inches Hg by .varying
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No. 14-05-79 - 12 -
the length of time the armature rests in the on (full 5
inches Hg (17 kPa) vacuum) or off (0 inches Kg (0 kPa)
vacuum) position. The rapid up-down motion of the armature
determines the average vacuum supplied to the carburetor.
Control of the ratio of time "on" to time "off" is deter-
mined by the feedback carburetor controller through the
electrical signal to the solenoid.
SYSTEM OPERATION
Purpose
As was seen earlier (Figure 3), a three-way catalyst is most
efficient in controlling HC and CO when the air-to fuel ratio
is leanest and there is an excess of oxygen; however, under
this condition, control of NOx is poor. On the other hand,
when the air-to-fuel ratio is rich and there is a deficiency
of oxygen, the control of NOx is good but control of HC and
CO is poor. At the chemically correct mixture, a narrow
"window" exists about the stoichiometric region (14.7:1 air-
to-fuel ratio) where the control of all three pollutants is
quite good. Maintaining the exhaust constituents at this
precise value at which the three-way catalytic converter is
most effective is the purpose of the EFC system.
Operating Modes
The EFC system can operate in two distinct modes, open loop
and closed loop. During closed loop operation, the system
is responsive to exhaust gas oxygen levels as indicated by
the oxygen sensor. In the open loop mode, the system operates
in response to preprogrammed electronic commands and signals
other than those from the oxygen sensor.
Closed'Loop Operation
In the closed loop mode, the feedback system is operational
and continuously corrects the air-to-fuel ratio toward a
stoichiometric mixture. Figure 11 shews a block diagram of
sensing and actuating elements that interact to form a loop.
Each component is sensitive to the performance of the upstream
component and responds by communicating to the down-stream
component.
Closed loop operation will not begin until the engine coolant
temperature reaches 150°F (66°C). This permits the oxygen
sensor and three-way catalyst to warm to operating temperatures.
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No. 14-05-79
- 13 -
AIR
INTAKE
I ENGINE I
RPM
ESC COMPUTER
EFC CONTROLLER
COMBUSTION
COMPUTER
EFC SYSTEM BLOCK DIAGRAM
At exhaust temperatures over 660°F {350°C), the zirconium
dioxide electrolyte allows the passage of oxygen ions from
one electrode to the other while blocking the passage of
others. The resulting oxygen pressure differential produces
a voltage output signal that varies in strength depending
on the relative availability of oxygen.
The sensor has the unique property of producing an abrupt
•change in voltage output precisely when the supply of exhaust
gas oxygen departs from the stoichiometric (14.7 tol) air-to-
fuel ratio necessary for optimum three-way catalyst efficiency
(Figure 6). Because of this characteristic, the sensor output
voltage can be used as an indication of when the system is
operating richer or leaner than desired.
When the exhaust gas oxygen content is low, as it would be
with a rich mixture, the voltage output will be high, indicating
a leaner mixture is required. Similarly, a voltage output that
is low means the oxygen content is too high and that a richer-
mixture is needed. Thus, the EFC system does not run at a
constant 14.7 to 1 air-to-fuel ratio, but fluctuates closely
about it. It constantly corrects to stoichiometric by
monitoring sensor voltage signals and issuing "rich" or
"lean" commands to drive the system to stoichiometry.
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No. 14-05-79
- 14 -
The output voltages from the sensor are evaluated by the
controller along with signals from the other system sensors.
This processing results in an electrical output signal to
the solenoid-vacuum regulator valve. By rapid switching of
the solenoid and control of the relative "on" to "off" time,
vacuum levels between 0 and 5 inches Hg (17 kPa) can be
provided as control vacuum to the carburetor. Figure 12
provides two examples of the chain of events that occurs
continuously to drive the air-to-fuel ratio toward a stoi-
chiometric mixture. .
An added benefit of the EFC system is its built-in ability
to maintain mixture constant at varying altitudes, eliminating
the mixture enrichment which normally occurs when a car is
driven to higher altitudes.
ENGINE
OPERATING— •-
CONDITION
RICH
OF
STOICHIOMETRY
EXHAUST GAS
OXYGEN
HIGH
OUTPUT
. VOLTAGE
(>.4 VOLT)
FEEDBACK
— CARBURETOR— •-
CONTROLLER
DIRECTS
VAC. SOL.-REG.
TO GREATER
"ON" TIME
SOLENOID
VACUUM ..
REGULATOR
VALVE
INCREASED
DUTY CYCLE
RESULTS
IN HIGHER
OUTPUT
VACUUM
VACUUM SIGNAL
TO
FEEDBACK
CARBURETOR
INCREASING
SIGNAL PULLS
DIAPHRAGMS
UPWARD
POSITION
— — OF IDLE -1
DIAPHRAGM
HIGHER POSITION
FOR INCREASE
IN AIR BLEED
(INCREASES
ORIFICE)
POSITION
.._ OF MAIN m
CVCTCU ™""'^
DIAPHRAGM
HIGHER
POSITION
FOR DECREASE
IN FUEL FLOW
(DECREASES
ORIFICE)
RESULTANT
CORRECTIONS
TOWARD
LEAN
LEAN
LOW
DIRECTS
DECREASED DECREASING SIGNAL LOWER POSITION LOWER POSITION TOWARD
RICH
OF
STOICHIOMETRY
OUTPUT
VOLTAGE
((.4 VOLT)
VAC. SOL.-REG.
TO LESS
"ON" TIME
DUTY CYCLE
RESULTS
IN LOWER
OUTPUT
VACUUM
ALLOWS DIAPHRAGM
SPRINGS TO MOVE
DIAPHRAGMS
DOWNWARD
FOR DECREASE
IN AIR BLEED
(DECREASES
ORIFICE)
FOR INCREASE
IN FUEL FLOW
(INCREASES
ORIFICE)
Oj SENSOR OUTPUT
RICH
•LEAN
RPM
MANIFOLD J
VACUUM
3 DUTY CYCLE
AIR-
TEMP
CLOSED LOOP OPERATING SEQUENCE
Open Loop Operation
The Feedback Carburetor Controller also directs operation of
the EFC system during periods when the air-fuel ratio informa-
tion from the oxygen sensor is interrupted (open loop modes).
This occurs under any of the following conditions, as explained
below.
-------
No. 14-05-79 - 15 -
o Coolant temperature below 150°F (66°C)
o Oxygen sensor temperature below 660°F (350°C)
o Low manifold vacuum
o Oxygen sensor default
o Hot engine starting
During start-up and acceleration, the controller is programmed
to ignore signals from the oxygen sensor, allowing the carbu-
retor to produce temporarily richer mixtures for good performance.
When the engine is warming up, the air injection system supplies
air to the exhaust manifold — upstream of both catalytic con-
verters — to provide extra oxygen for more complete burning
within the catalytic converter of hydrocarbons and carbon monoxide
emissions that tend to develop at lower operating temperatures.
(NOx is not a problem at this time since oxides of nitrogen
develop only at higher combustion temperatures). This extra
burning raises temperatures within the exhaust system and causes
the oxygen sensor and three-way catalyst to warm up faster."
During this period, the three-way catalytic converter functions
as an oxidation catalyst. After the engine is warmed up and
oxygen sensor and catalyst operating temperatures are reached,
an air switching valve diverts air flow from the exhaust ports
to enter the exhaust downstream from the three-way catalyst and
just ahead of the oxidation catalyst. At this point, the exhaust
is hot enough to oxidize the unburned HC and CO. Again, the addi-
tion of injected air is required in the oxidation process.
Low-Vacuum Sensor: Upon acceleration with a cold engine, if
the throttle is open sufficiently so that manifold vacuum drops
below 4.5 inches Hg (15 kPa), a vacuum signal will be supplied
to the Feedback Carburetor Controller which will enrich the
air-fuel mixture even further to prevent engine stalls, sags,
or stumbling and enhance driveability. After the engine -has
warmed'up and the system is under the control of the oxygen
sensor (closed loop mode), the system will revert to the open
loop mode whenever the manifold vacuum drops below 3 inches
Hg (10 kPa). This signal is to assure a sufficiently-rich
mixture for power and performance when accelerating from
cruising speeds. After acceleration, manifold vacuum will
return to a higher level and closed loop operation will resume.
Different vacuum signal values are used during open and closed
loop modes because less enrichment is required for acceleration
when fully warmed up than for acceleration during warm-up.
-------
No. 14-05-79 ~ 16 -
Coolant Temperature Sensing Switch: A coolant temperature
sensing switch, located in the cylinder head,
electrical circuit to the Feedback Carburetor Controller when
engine coolant reaches a temperature of 150°F (66°C). At
this point, the oxygen sensor is sufficiently warm to start
functioning. When this occurs, operation begins in response
to signals from the sensor.
Open loop operation terminates when there is sufficient vacuum
and the engine coolant and oxygen sensor are at their proper
operating temperatures. It may happen, however, under pro-
longed idle at low ambient temperatures that the oxygen sensor
may cool off enough so that it will not function properly.
This condition will be detected electronically from the sensor
and the system will compensate accordingly until the sensor
is again warm. The sensor will warm up very quickly once the
car is accelerated away from idle.
-------
No. 14-05-79 - 17 -
DIAGNOSTICS
The following test equipment is needed for diagnosis of the
EFC system:
o Vacuum gauge - 0-5" Hg (accurate within t 1/2"
in that range)
o Vacuum gauge - 0-30" Hg
o Hand pump with vacuum gauge
o Two short length of 3/16" I.D. vacuum tubing
o Two 3/16" tee
o Jumper wire (approximately 5 feet)
In general a malfunction of the EF.C system can be diagnosed
by observing the action of a vacuum gauge connected so as to
observe the control vacuum from the solenoid-regulator to
the carburetor.
A malfunction of the EFC system can cause such problems as:
o Surge
o Hesitation
o Rough Idle
o Poor Fuel Economy
The following checks should be made prior to performing any
diagnostic tests:
o Check all vacuum hoses for proper hook up. (Refer
to hose routing label located underhood) and for
kinks or other damage.
o Check all electrical connections and for frayed,
cracked or broken wiring. Refer to wiring diagram.
o Check the intake and exhaust manifolds for leakage.
-------
No. 14-05-79 - 18 -
Determining the Problem
With the vehicle fully warmed-up, the 0-5" Hg vacuum gauge
is teed into the control vacuum signal to the carburetor.
The vehicle is started and allowed to idle while the vacuum
gauge is observed. The gauge should indicate a steady 2.5"
Hg reading for approximately 100 seconds after starting, drop
to 0", and then gradually rise to between 1.0 and 4.0" Hg
average. The reading will oscillate about + 0.5" Hg.
If the gauge does not indicate in the above area, the engine
speed should be raised to approximately 2000 rpm and the
reading observed again. If the reading is between 1.0 and
4.0" Hg, the engine should be returned to idle to determine
if the reading there is now between 1.0 and 4.0" Hg. If
the reading at idle is within the proper range, it indicates
the oxygen sensor was not fully warmed originally and the
system is operating properly and other areas should be checked
to resolve the complaint.
If the gauge reads in the proper range at 2000 rpm and does
not at idle, it means the idle mixture is out of adjustment
and the carburetor must be replaced.
The following procedures should be undertaken to determine
the cause of the problem if the control vacuum is above 4"
Hg or below 1.0" Hg. It should be noted that for most system
malfunction conditions the control vacuum is typically at
either 0" Hg or 5" Hg.
CONTROL VACUUM ABOVE 4" Ha
If in the previous tests the control vacuum was consistently
above 4" Hg, the problem could be found in the following
components:
o Carburetor
o Carburetor Heat Shield
o Solenoid - Regulator
r
o Combustion Computer
o Oxygen Sensor
-------
No. 14-05-79 - 19 -
The engine is started and with the transmission in Neutral,
the throttle is placed on the next to the lowest step of the
fast idle cam. The following steps are then taken to deter-
mine the cause of the problem.
STEP 1
•» • • •
Carburetor
Since a high control vacuum indicates:that the system is
trying to correct for a rich mixture, the following test
should be made to determine if the mixture, is in fact too
rich. Remove the PCV hose from the PCV valve and cover the
end with your thumb. Gradually uncover the end of the hose
until the engine begins running roughly indicating a very
lean mixture. If the control vacuum to the carburetor gradu-
ally gets lower as more of the PCV hose is uncovered, it
indicates the carburetor was too rich and the carburetor
should be replaced; however, step 2 should be completed before
the carburetor is replaced. If the control vacuum remains high,
the problem is in another area of the system.
STEP 2
Carburetor Heat Shield
Prior to replacing the carburetor as indicated by Step 1, an
inspection should be made to determine if an interference
exists between the carburetor heat shield and the mechanical
power enrichment valve actuating lever at the rear of the
carburetor. If there is an interference, it will cause the
carburetor to be too rich.
A new heat shield has been released for 1979
model year. This was done to provide clearance
for the mechanical power enrichment lever and
the throttle position transducer actuating
lever. The earlier heat shield is not recommended
but could be used if modified for clearance.
STEP 3
Solenoid - Regulator
Disconnect the electrical connector to the device. The control
vacuum to the carburetor should drop to zero. If it does not,
replace the solenoid - regulator.
-------
No. 14-05-79 - 20 -
STEP 4
Combustion Computer
Disconnect the oxygen sensor wire and with a jumper wire
connect the harness lead to the battery negative terminal.
CAUTION: DO NOT CONNECT THE WIRE FROM THE OXYGEN SENSOR
TO BATTERY OR GROUND.
The control vacuum should gradually lower to 0" in about 15
seconds. If it does not, replace the computer. If it does,
replace the oxygen sensor.
NOTE: Prior to replacing computer or sensor, make sure wire
between the two is okay.
CONTROL VACUUM BELOW 1.0" Hg
If in the preliminary tests the control vacuum was consistently
below 1.0" Hg, the problem could be found in the following areas:
o Lack of vacuum to the computer vacuum transducer
o Carburetor
o Air switching system
o Solenoid - Regulator
o Wiring Harness
o Combustion Computer
o Oxygen Sensor
STEP 1
Lack of Vacuum to Computer Vacuum Transducer,
r
With engine at idle Neutral, disconnect the vacuum hose at
the computer transducer and connect the hose to a vacuum (0-30" Hg)
gauge. The gauge should .read manifold vacuum (in excess of 12" Hg)
If it does not, trace the hose to its source•and then connect it
properly (to a source of manifold vacuum)*
The remaining steps should be performed with
the transmission in Neutral and the throttle
on the next to the lowest step of the fast
idle cam, parking brake applied.
-------
No. 14-05-79 - 21 -
STEP 2
Carburetor
Since a low control vacuum is indicative of the system
trying to correct for a lean mixture, the following test
should be made to determine if the mixture is in fact too
lean. The air cleaner cover is removed and the choke blade
is gradually closed until the engine begins running roughly
thus indicating a very rich mixture. If the control vacuum
to the carburetor gradually increases to 5" Hg as the choke
is closed, it indicates either the carburetor was too lean
or the air switching system was not functioning properly
(go to Step 3). • If the control vacuum remains low, it
indicates the problem is in another area of the system
(go to Step 4).
STEP 3
Air Switching System
Disconnect the air injection hose at the metal tube that
leads to the rear of the cylinder head and plug the tube.
If the control vacuum remains below 1.0" Hg, replace the
carburetor. If the control vacuum returns to the proper
range, reconnect the air injection hose and disconnect the
3/16" vacuum hose from the air switching valve. If the
control vacuum remains below 1.0" Hg, replace the air
switching valve. If the control vacuum returns to the
proper range, check the vacuum hose routings for proper
connections and if the connections are correct, replace
the vacuum coolant switch (CCVES).
STEP 4
Solenoid - Regulator
Before testing the solenoid - regulator, verify
that the bottom nipple is connected to the
manifold vacuum.
Disconnect the electrical connector to the solenoid - regu-
lator. Connect a jumper wire from the positive terminal of
the battery to one terminal of the solenoid - regulator lead.
Connect the other terminal of the solenoid - regulator lead
to ground. The control vacuum should go above 5" Hg. If it
does not, replace the solenoid - regulator. If it does, go
to Step 5.
-------
No. 14-05-79
22 -
STEP 5
Wiring Harness
Disconnect the 5-way connector at the computer. Connect
a jumper wire from terminal 2 in harness to ground. The
control vacuum should go to 5" Hg. If it does not, trace
the wire back to the battery to find where the voltage is
lost. If it does, go to Step 6.
O
•MI
2
©
^
5
NOTE: Almost all problems associated with the wiring harness
will be caused by the connectors. Make sure connectors
are firmly snapped in place and there is no corrosion
or frayed wires causing poor contact.
STEP 6
Combustion Computer
Disconnect the oxygen sensor wire and with a jumper wire,
connect the harness lead to the battery positive terminal.
CAUTION: Do not connect the wire from the oxygen sensor
to battery or ground.
The control vacuum should gradually rise to 5" Hg in about
15 seconds. If it does not, replace the computer. If it
'does, replace the oxygen sensor.
-------
No. 14-05-79 - 23 -
OXYGEN SENSOR - Removal and Installation
Removal
Disconnect battery cable, remove air cleaner. Disconnect
oxygen sensor connector. Remove sensor using Special
Tool C-4589.
Inspection
Inspect wire and connector for signs of degradation. If
insulation is frayed to extent that connector or terminal
is visible, replace sensor. Inspect water splash shield
which is a metal band running around the upper portion
(sleeve) of the sensor and covers the vent holes. If
splash shield is not intact, replace sensor.
Installation
Coat threads of sensor with a nickel base anti-sieze compound
such as Loctite LO-607 or Never Seez NSN, or equivalent.
Do not use graphite or other type compounds as these could
electrically insulate the sensor from the manifold. Start
sensor by hand and torque to (35 + 5 foot-pounds) using
Special Tool C-4589. Install air cleaner assembly. Recon-
nect battery cable.
-------
No. 14-05-79 - 25 -
CARBURETOR SPECIFICATIONS
Accelerator Pump 1-3/4"
Dry Float Setting (± 1/32") Flush with top of bowl cover gasket
Bowl Vent 1/16"
Vacuum Kick .150"
Fast Idle Cam .080"
Choke Unloader .250"
Basic Timing 15° BTDC
Idle set speed 750
Fast Idle Speed 1800
-------
No. 14-05-79 ~ 24 "
IGNITION TIMING PROCEDURE
1. Ground the carburetor switch with a jumper wire.
2. Connect a suitable timing light to ignition system.
3. Start the engine.
4. Wait one minute after step 3.
5. With the engine running at a rpm not greater than the
specified curb idle rpm, adjust timing to specifications,
6. Remove ground wire and timing light.
CURB IDLE SET PROCEDURE*
1. Start and run engine in Neutral on the second step of
the fast idle cam until thermostat is open (engine
fully warmed up) and the radiator becomes hot. This
may take 5-10 minutes.
2. Disconnect and plug the EGR hose at the EGR valve.
3. Ground carburetor switch with a jumper wire.
4. Adjust the idle rpm in Neutral to the curb idle rpm
specification located on the Vehicle Emission Control
Information Label.
5. Reconnect the EGR hose and remove jumper wire from the
ground switch.
*Only after timing is known to be within specification.
-------
If I
U LJ ELECTRIC r"7 ELECTRIC
CHOKE ^-f CHOKE
I (CONTROL —
VACUUM
REGULATOR
VALVE
MILEAGE
SWITCH
I
m
o
i
IGNITION
COIL
THROTTLE
POSITION
TRANSDUCER
CONNECTOR
COOLANT
SENSOR
CARS
SWITCH
SINGLE
COMPUTER
CONNECTOR
CHANGE
TEMPERATURE
SWITCH
TEMPERATURE
GAUGE SENDING
UNIT
DISTRIBUTOR
CONNECTOR
OXYGEN
SENSOR
-------
No. 14-05-79
- 26 -
COMPONENT IDENTIFICATION
(EMISSION RELATED)
ITEM
Air Pump Pulley
with Chrysler A/C
with Sankyo A/C
without A/C
Air Switching/Diverter Valve
Carburetor (Holley R-8286A)
CCEVS Switch
Choke Assembly
Charge Temperature Switch
Distributor
EGR Vacuum Amplifier
EGR Valve
All except wagons
Wagons
Electric Choke Control
Emission Control Information Label
Combustion Computer
Coolant Switch
Spark Plugs
EGR Timer
Vacuum Hose Routing Label
Vacuum Solenoid
Vapor Canister
IDENTIFICATION NUMBER*
"4173221
4071720
4071720
4105053
4095909
4006587
4095336
4111482
4091490
4041732
4104009
4104008
4091036
4173883
4111373
4091719
4091678 (RBL-16Y)
4111481
4173258
3874027
3577595
*This number is located on either a label or stamped
into part. It does not represent a service replacement
number. Refer to the appropriate Parts Catalog for
this information.
-------
FTP (gms/miiu)
Date
6-29- 7'J '
7-2-79
7-3-79
7-9-79
7-10-79
7-1L-79 :
7-13-79 7
7-16-79 7
Date
6-29-79
7-2-79
7-3-79
7-9-79
7-10-79
7-11-79
7-13-79
7-16-79
Note: HC
CO
^st Number HC CO
i-si.H.W .40 4.5
j-8150,51 .41 3.7
9-8152,53 .34 3.3
i-8154,55 .40 1.9
•J-8156.57 .62 7.6
V-8138.59 1.03 29.8
V-8160,61 .40 3.7
•j-8162,63 .43 3.7
Test Numbers
79-8148, 49
79-8150, 51
79-8152, 53
79-8154, 55
79-8156, 57
79-8158, 59
79-8160, 61
79-8162, 63
values in ppm Hexane.
C02 NOx
527 .91
518 .89
507 1.39
494 1.15
551 .60
473- .40
504 1.81
521 .89
HC/CO
F.E.
16.6
16.9
17.3
17.8
15.7
17.0
17.4
16.8
HC/CO
Raw
HC
65
60
28
85
33
230
50
30
(ppm/%)
CO HC
.02 .067
.02 .070
.03 .079
.03 .066
.04 .050 2
. 09 . 082 5
.03 .057
.03 .063
Federal Three
HC/CO HC/CO
52 mph
10/.02
10/.018
12/.025
10/.02
10/.15
15/.25
10/.05
10/.04
10/.02
10/.018
22/.035
10/.02
12/.15
12/.17
10/.03
10/.03
15/
15/
18/
10/
10/
13/
10/
10/
25 mph
.02 15/.018
.02 12/.02
.05 22/.055
. 02 10/ . 02
.06 12/.06
.45 12/.35
.04 10/.04
.03 10/.03
met (ems/mile)
CO C02 NOx
.276 415.3 1.848
.286 414.6 1.967
.121 404.6 3.566
.199 408.7 2.059
.134 490.5 .725
.543 396.8 1.185
.136 419.9 5.834
.174 405.5 2.021
Mode
HC/CO HC/CO
Idle (Drive)
20/.01 20/.011
25/.018 20/.011
22/.04 22/.055
15/.02 25/.02
30/.04 25/.02
85/.60 175/.70
50/.05 25/.03
20/.03 18/.025
Raw (ppm/X)
F.E. HC CO
21.3 55 .025
21.4 40 .02
21.9 25 .02
21.7 35 .02
18.0 18 .02
21.9 120 .7
21.1 20 .03
21.8 15 .02
HC/CO HC/CO
Idle (Neutral)
30/.01 28/.016
43/.018 30/.01
22/.04 33/.055
60/.02 30/.02
35/.02 30/.02
200/.80 250/.75
80/.05 70/.04
35/.03 35/.03
NYCC (ems/mile)
HC CO C02 NOx F.E.
.907 4.111 831.6
.898 3.745 829.2
1.090 8.340 817.25
.889 2.996 829.17
1.084 21.013 927.65
1.838 33.818 784.3
.691 2.572 830.4 1
.644 2.959 860.6
Loaded
HC/CO HC/CO
30 mph
10/.02 10/.02
11/.016 10/.017
25/.05 22/.055
10/.02 10/.02
18/.07 18/.07
18/.33 12/.25
10/.04 10/.04
10/.03 10/.03
.550 10.5
.630 10.6
.533 10.6
.726 10.6
.511 9.2
.664 10.5
.378 10.6
.748 10.2
Two Mode
HC/CO
Raw ppm/ Z
HC CO
49 .16
90 .022
43 .016
75 .02
42 .06
250 .65
50 .04
60 .04
HC/CO
Idle (Neutral)
15/.02
25/.015
20/.02
35/.02
25/.02
HO/. 55
70/.04
35/.03
30/.011
28/.014
22/.055
25/.015
30/.02
70/.50
35/.03
25/.02
Test Comments
*f:
B/L
EGO Sen. Disc.
CTS Disc.
Sol. Vac. Reg. Disc.
A.I. Bypassed
ECR Disc.
B/L
B/L
B/L
ECO Sen. Disc.
CTS Disc.
Sol. Vac. Reg. Disc.
A.I. Bypassed
ECR Disc.
B/L
-------
Date
Test Number
6-29-79
7-2-79
7-3-79
7-9-79
7-10-79
7-11-79
7-13-79
7-16-79
79-8148.
79-8150,
79-8152,
79-8154,
79-8156,
79-8158,
79-8160,
79-8162,
49
51
53
55
57
59
61
63
Two Speed Idle Cycle
HC/CO HC/CO
Neutral
40/.016
28/.015
28/.02
30/.1
30/.02
130/.55
60/.04
30/ . 03
40/.018
27/.016
38/.05
25/.02
30/.02
ISO/. 60
55/.04
30/.025
HC/CO
2500
10/.02
12/.017
22/.025
10/.02
25/.09
15/.45
10/.04
10/.03
HC/CO
rpm
15/.02
12/.020
18/.04
10/.02
20/.9
15/.35
10/.04
10/.03
HC/CO HC/CO
Idle (Neutral)
55/.13
22/.017
90/.03
45/.02
40/.03
140/.80
40/.03
25/.02
45/.016
20/.012
38/.04
25/.02
40/.02
80/.45
30/.03
30/.02
Abbreviated I/K Idle Cycle
HC/CO
HC/CO
Idle (Neutral)
35/.02
30/.018
30/.03
50/.02
40/.03
140/.80
40/.03
50/.02
22/.010
42/.04
35/.02
40/.02
80/.45
30/.03
HC/CO
HC/CO
25/.02 30/.02
Idle (Neiitral) Test Comments
45/.10 30/.02 B/L
22/.018 24/.010 B/L
35/.03 SO/.05 ECO Sen. Disc.
35/.02 30/.02 CTS Dls.
40/.03 40/.02 Sol. Vac. Reg.bisc.
150/-.77 90/.50 A.I. Bypassed
40/.04 30/.03 ECR Disc.
30/.03 30/.025 B/L
Note: HC values In ppm Hexane.
CO values In percent.
Prolonged Idle Cycle HC/CO
Date
6-29-79
7-2-79
7-3-79
7-9-79
7-10-79
7-11-79
7-13-79
7-!t>-79
Test Number
79-8148, 49
79-3150, 51
79-8152, 53
7-J-8154, 55
75-8156, 57
79-U158, 59
79-8160,
79-BJ62,
61
63
Int.
20/.02
20/.011
50/.05
40/.02
40/.02
100/.60
30/.03
1
30/.02
22/.017
38/.03
50/.02
35/.02
200/.65
55/.04
2
35/.02
"25/.017
44/.03
60/.02
38/.005
175/.60
60/.04
3
50/.02
35/.018
44/.03
70/.02
40/.05
225/.60
70/.04
4
55/.02
30/.018
40/.02
75/.02
40/.07
240/.55
80/.04
5
60/.
•SO/.
58/.
100/.
40/.
185/.
80/.
02
018
02
02
07
55
04
6
85/.02
45/.018
58/.02
85/.02
45/.07
230/.65
100/.05
7
80/.02
SO/. 012
45/.02
110/. 02
45/.07
2 SO/. 50
110/. 05
8
70/.03
so/.o:.6
SO/. 02
80/.02
40/.03
250/.60
95/.0*
9
80/.02
50/.015
53/.02
HO/. 02
42/.09
250/.60
100/.05
10 '
65/.02
50/.015
70/.02
95/.02
42/.09
250/.60
90/.04
B/L
B/L
EGO Sen. Disc.
CTS Disc.
Sol. Vac. Reg. Disc.
A.I. Bypassed
EGR Disc.
30/.025 30/.03 40/.04 45/.04
65/.04
60/.04 60/.04 75/.04 90/.0.i 100/.045 100/.045 B/L
3-
a
* US. GOVERNMENT PRINTING OFFICE: 1979- 651-112/0070
------- |