torque CHEVROLET DYNASTY 1993 Service Manual

FUEL SYSTEM PRESSURE RELEASE PROCEDURE
WARNING: RELEASE FUEL SYSTEM PRESSURE
BEFORE SERVICING FUEL SYSTEM COMPONENTS.
WHEN SERVICING FLEXIBLE FUEL VEHICLES,
WEAR METHANOL RESISTANT GLOVES AND EYE
PROTECTION AND AVOID BREATHING FUMES. DO
NOT ALLOW METHANOL/GASOLINE MIXTURES TO
CONTACT SKIN. SERVICE VEHICLES IN WELL VEN-
TILATED AREAS AND AVOID IGNITION SOURCES.
NEVER SMOKE WHILE SERVICING THE VEHICLE.
(1) Disconnect negative cable from battery.
(2) Remove fuel filler cap.
(3) Remove the protective cap from the fuel pres-
sure test port on the fuel rail (Fig. 2).
(4) Place the open end of fuel pressure release
hose, tool number C-4799-1, into a container ap-
proved for methanol/gasoline mixtures. Connect the
other end of hose C-4799-1 to the fuel pressure test
port (Fig. 3). Fuel pressure will bleed off through the
hose into the gasoline container. Fuel gauge
C-4799-A contains hose C-4799-1.
THROTTLE POSITION SENSOR (TPS)
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Disconnect harness connector from throttle po-
sition sensor (Fig. 4). (3) Remove throttle position sensor mounting
screws. (4) Lift throttle position sensor off throttle shaft.
INSTALLATION
(1) Install throttle position sensor on throttle shaft.
Install mounting screws. Tighten screws to 2 N Im (17
in. lbs.) torque. (2) Attach harness connector to sensor.
(3) Connect negative cable to negative post of the
battery.
IDLE AIR CONTROL MOTOR
REMOVAL
(1) Disconnect negative cable from battery.
(2) Disconnect harness connector from idle air con-
trol motor (Fig. 5).
Fig. 1 Throttle Body
Fig. 2 Fuel Pressure Test Port
Fig. 3 Releasing Fuel Pressure
Fig. 4 Servicing Throttle Position Sensor
14 - 78 FUEL SYSTEMS Ä

(3) Remove idle air control motor mounting screws.
(4) Remove idle air control motor from throttle
body (make certain that the O-ring is on motor).
INSTALLATION
(1) New idle air control motors have a new O-ring
installed on them. If pintle measures more than 1
inch (25 mm) it must be retracted. Use the IDLE
AIR CONTROL MOTOR OPEN/CLOSE mode of the
DRBII scan tool (battery must be reconnected for this
operation). (2) Carefully place idle air control motor into
throttle body. (3) Install 2 mounting screws. Tighten screws to 2
N Im (17 in. lbs.) torque.
(4) Connect harness connector to motor.
(5) Connect negative cable to battery.
THROTTLE BODY REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove clamp from air hose. Remove hose (Fig.
1). (3) Remove accelerator cable.
(4) Disconnect idle air control motor and throttle
position sensor (TPS) electrical connectors. (5) Remove throttle body mounting nuts.
(6) Remove throttle body and gasket.
(7) Reverse the above procedures for installation.
FUEL INJECTOR RAIL ASSEMBLY
WARNING: RELEASE FUEL SYSTEM PRESSURE
BEFORE SERVICING FUEL SYSTEM COMPONENTS.
WHEN SERVICING FLEXIBLE FUEL VEHICLES,
WEAR METHANOL RESISTANT GLOVES AND EYE
PROTECTION AND AVOID BREATHING FUMES. DO
NOT ALLOW METHANOL/GASOLINE MIXTURES TO
CONTACT SKIN. SERVICE VEHICLES IN WELL VEN-
TILATED AREAS AND AVOID IGNITION SOURCES.
NEVER SMOKE WHILE SERVICING THE VEHICLE.
REMOVAL
(1) Perform fuel system pressure release procedure.
(2) Disconnect negative cable from battery.
(3) Disconnect the fuel injector harness connector
from the engine harness (Fig. 6).
(4) Remove the quick connect fittings from the
chassis fuel tubes. Refer to Quick Connect Fittings in
the Fuel Delivery section of this group. (5) Disconnect the vacuum hose from the top of the
intake manifold (Fig. 6). (6) Disconnect vacuum hose from the pressure reg-
ulator (Fig. 6). (7) Remove screw from the fuel tube clamp (Fig.
6). (8) Remove fuel rail mounting screws.
(9) Pull up on the injector rail. The injectors will
pull straight out of the ports. Do not damage the in-
jector O-rings. (10) Remove fuel rail assembly from vehicle. Do
not remove fuel injectors until fuel rail assembly has
been completely removed from vehicle. (11) Plug or cover intake manifold injector ports to
prevent dirt from entering the openings (Fig. 7).
INSTALLATION
WARNING: FUEL RAILS, INJECTORS AND PRES-
SURE REGULATORS DESIGNED FOR GASOLINE
ONLY VEHICLES CANNOT BE USED ON FLEXIBLE
FUEL AA-BODY VEHICLES. WHEN SERVICING THE
FUEL SYSTEM OF A FLEXIBLE FUEL VEHICLE,
ONLY USE ORIGINAL EQUIPMENT OR EQUIVA-
LENT REPLACEMENT COMPONENTS.
(1) Ensure injectors are seated into the receiver
cup on the fuel rail with the lock ring in place. (2) Attach harness connectors to injectors. Fasten
the harness into wiring clips.
Fig. 5 Servicing Idle Air Control Motor
Fig. 6 Injector Harness and Engine Harness Connection
Ä FUEL SYSTEMS 14 - 79

(3) Ensure the injector holes are clean and all plugs
have been removed. (4) Lubricate the injector O-rings with a drop of
clean engine oil to ease installation. (5) Install the injector assembly into their holes.
Install mounting screws. Fuel rail assembly must be
drawn into the intake manifold evenly making sure
each injector enters its own hole. Once all injectors are
seated, tighten bolts to 23 N Im (200 in. lbs) torque.
(6) Connect vacuum hose to fuel pressure regulator.
(7) Close fuel tube clip around fuel tubes and install
fastener. (8) Lubricate the ends of the chassis fuel tubes with
a light coating of clean 30 weight engine oil. Connect
fuel supply and return hoses to chassis fuel tube
assembly. Pull back on the quick connect fittings to
ensure complete insertion. Refer to Quick Connect
Fittings in the Fuel Delivery section of this group. (9) Connect vacuum hose intake manifold nipple.
(10) Connect negative cable to battery.
CAUTION: When using the ASD Fuel System Test, the
Auto Shutdown (ASD) Relay remains energized for
either 7 minutes, until the test is stopped, or until the
ignition switch is turned to the Off position.
(11) With the DRBII scan tool, use the ASD Fuel
System Test to pressurize system and check for leaks.
FUEL INJECTOR
The fuel rail must be removed to service the injec-
tors. Refer to Fuel Injector Rail Assembly in this
section.
REMOVAL
WARNING: RELEASE FUEL SYSTEM PRESSURE BE-
FORE SERVICING FUEL SYSTEM COMPONENTS.
WHEN SERVICING FLEXIBLE FUEL VEHICLES,
WEAR METHANOL RESISTANT GLOVES AND EYE
PROTECTION AND AVOID BREATHING FUMES. DO NOT ALLOW METHANOL/GASOLINE MIXTURES TO
CONTACT SKIN. SERVICE VEHICLES IN WELL VEN-
TILATED AREAS AND AVOID IGNITION SOURCES.
NEVER SMOKE WHILE SERVICING THE VEHICLE.
(1) Disconnect electrical connector from injector
(Fig. 8).
(2) Position fuel rail assembly so that the fuel injec-
tors are easily accessible (Fig. 9). (3) Remove injector lock ring from fuel rail and
injector. Pull injector straight out of fuel rail receiver
cup. (4) Check injector O-ring for damage. Replace dam-
aged O-rings. If injector is reused, install a protective
cap on the injector tip to prevent damage. (5) Repeat steps for remaining injectors.
INSTALLATION
WARNING: FUEL INJECTORS AND INJECTOR
O-RINGS DESIGNED FOR GASOLINE ONLY VE-
HICLES CANNOT BE USED ON FLEXIBLE FUEL AA-
BODY VEHICLES. WHEN SERVICING THE FUEL SYS-
TEM OF A FLEXIBLE FUEL VEHICLE, ONLY USE
ORIGINAL EQUIPMENT OR EQUIVALENT REPLACE-
MENT COMPONENTS.
Fig. 7 Fuel Injector Ports
Fig. 8 Servicing Fuel Injectors
14 - 80 FUEL SYSTEMS Ä

INSTALLATION
WARNING: THE FUEL PRESSURE REGULATOR,
O-RING AND SPACER DESIGNED FOR GASOLINE
ONLY VEHICLES CANNOT BE USED ON FLEXIBLE
FUEL AA-BODY VEHICLES. WHEN SERVICING THE
FUEL SYSTEM OF A FLEXIBLE FUEL VEHICLE,
ONLY USE ORIGINAL EQUIPMENT OR EQUIVA-
LENT REPLACEMENT COMPONENTS.
(1) Lubricate new O-ring with a drop of clean en-
gine oil. Install spacer and O-ring into the receiver
cup on fuel rail (Fig. 13). (2) Install mounting nuts. Tighten nuts to 7 N Im
(65 in. lbs.) torque. (3) Connect fuel return tube to pressure regulator.
Using a wrench to hold the fuel pressure regulator,
tighten the nut to 28 N Im (150 in. lbs.) torque.
(4) Connect vacuum hose to pressure regulator. Re-
place clamp. (5) Connect negative cable to battery.
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) Relay remains energized
for either 7 minutes, until the test is stopped, or un-
til the ignition switch is turned to the Off position.
(6) With the DRBII scan tool, use the ASD Fuel
System Test to pressurize system and check for
leaks.
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
SERVICE
(1) Remove vacuum hose and remove mounting
screws from sensor (Fig. 14). (2) Remove wiring harness and remove sensor.
(3) Reverse the above procedure for installation.
PCM SERVICE
(1) Remove air cleaner duct from PCM.
(2) Remove battery.
(3) Remove PCM mounting screws (Fig. 15).
(4) Remove 60 way wiring connector from module
and remove module. (5) Reverse the above procedure for installation.
METHANOL CONCENTRATION SENSOR
Refer to the Fuel Delivery section of this group for
methanol concentration sensor service.
HEATED OXYGEN SENSOR (O2SENSOR)
The oxygen sensor is installed in the exhaust man-
ifold (Fig. 16).
CAUTION: Do not pull on the oxygen sensor wires
when disconnecting the electrical connector.
WARNING: THE EXHAUST MANIFOLD MAY BE EX-
TREMELY HOT. USE CARE WHEN SERVICING THE
OXYGEN SENSOR.
Fig. 13 Fuel Pressure Regulator Removal/InstallationFig. 14 Manifold Absolute Pressure Sensor
Fig. 15 PCM Removal/Installation
14 - 82 FUEL SYSTEMS Ä

(1) Disconnect oxygen sensor electrical connector.
(2) Remove sensor using Tool C-4907 (Fig. 17).
Slightly tightening the sensor can ease removal. When the sensor is removed, the exhaust manifold
threads must be cleaned with an 18 mm X 1.5 + 6E tap.
If using original sensor, coat the threads with Loctite
771-64 anti-seize compound or equivalent. New sen-
sors are packaged with compound on the threads and
do not require additional compound. The sensor must
be tightened to 28 N Im (20 ft. lbs.) torque.
2.2L TURBO III MULTI-PORT FUEL INJECTIONÐSYSTEM OPERATION
INDEX
page page
Air Conditioning Clutch RelayÐPCM Output .... 89
Air Conditioning Switch SenseÐPCM Input ..... 85
Auto Shutdown (ASD) Relay and Fuel Pump RelayÐPCM Output ..................... 89
Barometric Read SolenoidÐPCM Output ....... 90
Battery VoltageÐPCM Input ................ 85
Brake SwitchÐPCM Input .................. 85
Camshaft Position SensorÐPCM Input ........ 85
Canister Purge SolenoidÐPCM Output ........ 90
CCD Bus .............................. 84
Charge Air Temperature SensorÐPCM Input . . . 86
Crankshaft Position SensorÐPCM Input ....... 87
Data Link ConnectorÐPCM Output ........... 91
Engine Coolant Temperature SensorÐPCM Input . 86
Fuel InjectorÐPCM Output ................. 91
Fuel Injectors and Fuel Rail Assembly ......... 94
Fuel Pressure Regulator ................... 94
Fuel Supply Circuit ....................... 94
General Information ....................... 83
Generator FieldÐPCM Output ............... 89 Heated Oxygen Sensor (O
2Sensor)ÐPCM Input . 88
Idle Air Control MotorÐPCM Output .......... 90
Ignition CoilÐPCM Output .................. 91
Knock SensorÐPCM Input ................. 87
Malfunction Indicator Lamp (Check Engine)ÐPCM Output ............................... 90
Manifold Absolute Pressure (Map) SensorÐPCM Input ................................ 87
Modes of Operation ....................... 92
Powertrain Control Module ................. 84
Radiator Fan RelayÐPCM Output ............ 91
Speed Control SolenoidsÐPCM Output ........ 91
Speed ControlÐPCM Input ................. 88
System Diagnosis ........................ 84
TachometerÐPCM Output .................. 91
Throttle Body ............................ 94
Throttle Position Sensor (TPS)ÐPCM Input ..... 88
Vehicle Speed SensorÐPCM Input ........... 89
Wastegate Control SolenoidÐPCM Output ..... 91
GENERAL INFORMATION
The turbocharged multi-port electronic fuel injec-
tion system combines an electronic fuel and spark
advance control system with a turbocharged intake
system (Fig. 1). The fuel injection system is con-
trolled by the powertrain control module (PCM). The PCM regulates ignition timing, air-fuel ratio,
emission control devices, cooling fan, charging sys-
tem, speed control, turbocharger wastegate and idle
speed. The PCM adapts its requirement to meet
changing operating conditions. Various sensors provide the inputs necessary for
the PCM to correctly regulate fuel flow at the fuel
injector. These include the manifold absolute pres-
sure, throttle position, oxygen sensor, coolant tem-
perature, detonation, and vehicle speed sensors. In
addition to the sensors, the air conditioning clutch
switch and various relays provide important informa-
tion and system control. The outputs include the auto
shutdown relay and fuel pump relay. All inputs to the PCM are converted into signals.
Based on these inputs the PCM adjusts air-fuel ratio,
ignition timing, turbocharger wastegate and other
Fig. 16 Heated Oxygen Sensor
Fig. 17 Oxygen Sensor Socket
Ä FUEL SYSTEMS 14 - 83

INSTALLATION
(1) Install throttle position sensor on throttle shaft.
Install mounting screws. Tighten screws to 2 N Im (17
in. lbs.) torque. (2) Attach harness connector to sensor.
(3) Connect negative cable to negative post of the
battery.
IDLE AIR CONTROL MOTOR
REMOVAL
(1) Disconnect negative cable from battery.
(2) Disconnect harness connector from idle air con-
trol motor (Fig. 4). (3) Remove idle air control motor mounting screws.
(4) Remove the motor from throttle body. Ensure the
O-ring is was removed with the idle air control motor.
INSTALLATION
(1) New idle air control motors have a new O-ring
installed on them. If pintle measures more than 1 inch (25 mm) it must be retracted by using the IDLE
AIR CONTROL MOTOR OPEN/CLOSE mode of the
DRBII scan tool. (2) Carefully place idle air control motor into
throttle body. (3) Install mounting screws. Tighten screws to 2
N Im (17 in. lbs.) torque.
(4) Connect harness connector to motor.
(5) Connect negative cable to battery.
THROTTLE BODY REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove clamp from air hose. Remove hose (Fig.
5). (3) Remove accelerator cable.
(4) Disconnect idle air control motor and throttle
position sensor (TPS) electrical connectors (Fig. 6). (5) Disconnect vacuum hoses from throttle body.
(6) Remove throttle body to intake manifold at-
taching nuts (2). (7) Remove throttle body and gasket.
INSTALLATION
(1) Install throttle body with new gasket.
(2) Install throttle body attaching nuts. Tighten
nuts to 25 N Im (225 in. lbs.) torque.
(3) Connect vacuum hoses to the throttle body.
(4) Attach harness connectors to the throttle posi-
tion sensor (TPS) and the idle air control motor. (5) Install throttle and speed control cables (if ap-
plicable). (6) Install throttle body intake air hose. Tighten
clamp to 4 N Im (30 in. lbs.) torque.
(7) Connect negative cable to battery.
Fig. 4 Idle Air Control MotorFig. 2 Fuel Pressure Test Port
Fig. 3 Throttle Position Sensor
14 - 108 FUEL SYSTEMS Ä

(8) Cover or plug the injector ports with while ser-
vicing the injectors (Fig. 9).
INSTALLATION
(1) Ensure the injectors are seated into the re-
ceiver cup, with the lock ring in place. (2) Ensure the injector wiring connectors are fully
inserted into the fuel injectors. (3) Make sure the injector holes are clean and all
plugs have been removed (Fig. 9). (4) Lubricate the injector O-rings with a drop of
clean engine oil. (5) Install the injector assemblies into their holes
and install the attaching bolts. Draw the fuel rail as-
sembly evenly into the intake manifold, making sure
each injector enters its own hole. The oil separator
bracket must be on top of the fuel rail bracket (Fig.
8). (6) Once all injectors are evenly seated, tighten the
fuel rail attaching bolts to 23 N Im (200 in. lbs.)
torque. (7) Connect the fuel injector wiring harness to the
main harness. (8) Lubricate the ends of the chassis tubes with
clean 30 weight engine oil. (9) Connect fuel hose quick connect fittings to the
chassis fuel tubes. Pull on the fittings to ensure com-
plete connection. Refer to Quick Connect Fittings in the Fuel Deliv-
ery Section of this group. (10) Connect the vacuum hose to the fuel pressure
regulator. (11) Connect negative cable to battery.
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) Relay remains energized
for either 7 minutes, until the test is stopped, or un-
til the ignition switch is turned to the Off position. (12) With the DRBII scan tool the ASD Fuel Sys-
tem Test to pressurize the fuel system to check for
leaks.
FUEL INJECTORS
Remove the fuel rail to service the injectors. Refer
to Fuel Injector Rail Assembly in this section.
REMOVAL
(1) Disconnect injector electrical connector from in-
jector. (Fig. 10).
(2) Position fuel rail assembly so that the fuel in-
jectors are easily accessible (Fig. 11).
(3) Remove injector lock ring off the fuel rail and
injector. Pull injector straight out of fuel rail receiver
cup (Fig. 11). (4) Check injector O-ring for damage. If O-ring is
damaged, it must be replaced. If injector is reused, a
protective cap must be installed on the injector tip to
prevent damage. (5) Repeat for remaining injectors.
Fig. 9 Fuel Injector Ports
Fig. 10 Fuel Rail and Injector Assembly
Fig. 11 Servicing Fuel Injectors
14 - 110 FUEL SYSTEMS Ä

INSTALLATION
(1) Before installing an injector, the rubber O-ring
must be lubricated with a drop of clean engine oil to aid
in installation. (2) Being careful not to damage the O-ring, install
injector top end into fuel rail receiver cup. (3) Install injector lock ring by sliding open end into
slot of the injector and onto the receiver cup ridge into
the side slots of ring (Fig. 11). (4) Repeat steps for remaining injectors.
(5) Install injector wiring harness to injectors. Place
harness into retaining clips.
FUEL PRESSURE REGULATOR
WARNING: THE 2.2L TURBO III FUEL SYSTEM IS
UNDER A CONSTANT PRESSURE OF APPROXI-
MATELY 380 KPA (55 PSI). PERFORM FUEL PRES-
SURE RELEASE PROCEDURE BEFORE SERVICING
THE FUEL PRESSURE REGULATOR.
REMOVAL
(1) Perform fuel system pressure release procedure.
(2) Disconnect negative cable from battery.
(3) Disconnect vacuum hose from fuel pressure regu-
lator (Fig. 12).
Place a shop towel under fuel pressure regula-
tor to absorb any fuel spillage. (4) Loosen fuel hose clamp and remove fuel return
hose. (5) Remove fuel pressure regulator mounting nuts.
Remove fuel pressure regulator from rail (Fig. 12).
Check O-Ring for damage. If O-Ring is damaged it
must be replaced.
INSTALLATION
(1) Lubricate O-ring with a drop of clean engine oil.
Install O-ring into the receiver cup on fuel rail. (2) Install fuel pressure regulator mounting nuts.
Tighten nuts to 7 N Im (65 in. lbs.) torque. (3) Connect fuel return hose to pressure regulator.
Tighten hose clamp to 1 N Im (10 in. lbs.) torque (Fig.
12). (4) Install vacuum hose on fuel pressure regulator.
(5) Connect negative cable to battery.
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) Relay remains energized
for either 7 minutes, until the test is stopped, or un-
til the ignition switch is turned to the Off position. (6) With the DRBII scan tool the ASD Fuel System
Test to pressurize system and check for leaks.
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
SERVICE
(1) Remove vacuum hose from MAP sensor (Fig.
13) (2) Remove MAP sensor mounting screws (Fig. 13).
(3) Remove electrical connector. Remove sensor.
(4) Reverse the above procedure for installation.
WASTEGATE AND CANISTER PURGE SOLENOID
SERVICE
(1) Remove vacuum hoses from sensors (Fig. 14).
(2) Disconnect electrical connector from solenoids
(Fig. 14). (3) Remove solenoid pack mounting nut. Remove
solenoid pack. (4) Depress tab on top of solenoid to be replaced
and slide the solenoid downward out of mounting
bracket. (5) Reverse above procedure to install.
PCM SERVICE
(1) Remove air cleaner duct from PCM.
(2) Remove battery.
(3) Remove PCM mounting screws (Fig. 15).
(4) Disconnect the 60-way wiring connector. Re-
move the PCM. (5) Reverse the above procedure for installation.
Fig. 13 Manifold Absolute Pressure Sensor
Fig. 12 Servicing Fuel Pressure Regulator
Ä FUEL SYSTEMS 14 - 111

HEATED OXYGEN SENSOR (O2SENSOR)
The oxygen sensor is installed in the exhaust man-
ifold (Fig. 16).
CAUTION: Do not pull on the oxygen sensor wires
when disconnecting the electrical connector.
WARNING: THE EXHAUST MANIFOLD MAY BE EX-
TREMELY HOT. USE CARE WHEN SERVICING THE
OXYGEN SENSOR. (1) Disconnect oxygen sensor electrical connector.
(2) Remove sensor using Tool C-4907 (Fig. 17).
Slightly tightening the sensor can ease removal.
When the sensor is removed, the exhaust manifold
threads must be cleaned with an 18 mm X 1.5 + 6E
tap. If using original sensor, coat the threads with
Loctite 771-64 anti-seize compound or equivalent.
New sensors are packaged with compound on the
threads and do not require additional compound.
Tighten the sensor to 27 N Im (20 ft. lbs.) torque.
Fig. 14 Solenoid Mounting
Fig. 15 PCM
Fig. 16 Heated Oxygen Sensor
Fig. 17 Oxygen Sensor Socket
14 - 112 FUEL SYSTEMS Ä

² Engine Coolant Temperature Sensor
² Distributor Pick-up
² Manifold Absolute Pressure (MAP) Sensor
² Oxygen Sensor
² SCI Receive
² Speed Control System Controls
² Throttle Position Sensor
² Park/Neutral Switch (automatic transaxle)
² Vehicle Speed Sensor
PCM Outputs:
² Air Conditioning Clutch Relay ²
Generator Field
² Idle Air Control Motor
² Auto Shutdown (ASD) and Fuel Pump Relays
² Canister Purge Solenoid
² Malfunction Indicator Lamp (Check Engine Lamp)
² Data Link Connector
² Electric EGR Transducer (EET)
² Fuel Injectors
² Ignition Coil
² Torque Converter Clutch Solenoid
² Radiator Fan Relay
² Speed Control Solenoids
² Tachometer Output
Based on inputs it receives, the PCM adjusts fuel
injector pulse width, idle speed, ignition spark ad-
vance, ignition coil dwell and canister purge opera-
tion. The PCM regulates the cooling fan, air
conditioning and speed control systems. The PCM
changes generator charge rate by adjusting the gen-
erator field. The PCM adjusts injector pulse width (air-fuel ra-
tio) based on the following inputs.
² battery voltage
² engine coolant temperature
² exhaust gas content
² engine speed (distributor pick-up)
² manifold absolute pressure
² throttle position
Fig. 1 Multi-Port Fuel Injection Components
Fig. 2 PCM
14 - 114 FUEL SYSTEMS Ä