1993 CHEVROLET PLYMOUTH ACCLAIM fuel cap

INSTALLATION
WARNING: FUEL TANKS DESIGNED FOR GASO-
LINE ONLY VEHICLES CANNOT BE USED ON
FLEXIBLE FUEL AA-BODY VEHICLES. WHEN SER-
VICING THE FUEL SYSTEM OF A FLEXIBLE FUEL
VEHICLE, ONLY USE ORIGINAL EQUIPMENT OR
EQUIVALENT REPLACEMENT COMPONENTS. (1) Position fuel tank on transmission jack. Con-
nect vapor separator/rollover valve hose and position
insulator pad on fuel tank. Position vapor vent so
that it is not pinched between tank and floor pan
during installation. (2) Raise tank and fuel filler tube carefully into
position. Use a light coating of power steering fluid
to ease fuel filler tube installation. Ensure filler tube
grommet is not damaged. Verify that the tube is in-
stalled correctly. (3) Tighten fuel tank strap nuts to 23 N Im (250 in.
lbs.) torque. Remove transmission jack. Ensure
straps are not twisted or bent. (4) Lubricate the metal tubes on the fuel pump
with clean 30 weight engine oil. Install the quick
connect fuel fittings. Refer to Quick Connect Fittings
in the Fuel Delivery section of this Group. (5) Attach electrical connector to fuel pump mod-
ule and level sensor unit. (6) Lower the vehicle.
(7) Attach filler tube to filler neck opening in
quarter panel. Tighten quarter panel screws to 2
N Im (17 in. lbs.) torque.
(8) Fill fuel tank, install filler cap, and connect
battery cable.
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.
(9) Use the DRBII scan tool ASD Fuel System Test
to pressurize the fuel system. Check for leaks.
FUEL PUMP MODULE
Refer to the Fuel Delivery section of this group.
METHANOL CONCENTRATION SENSOR
Refer to the Fuel Delivery section of this group.
FUEL RESERVOIR
The fuel reservoir is internal to the fuel pump as-
sembly (Fig. 6). The purpose is to provide fuel at the
fuel pump intake during all driving conditions, espe-
cially when low fuel levels are present.
FUEL TANK LEVEL SENSOR
DIAGNOSIS
This procedure test the resistance of the level sen-
sor itself. It does not test the level sensor circuit. Re-
fer to Group 8W, Wiring Diagrams for circuit
identification and Group 8E, Instrument Panel and
Gauges for fuel gauge information. The level sensor is a variable resistor. Its resis-
tance changes with the amount of fuel in the tank.
The float arm attached to the sensor moves as the
fuel level changes. To test the level sensor, connect
an ohmmeter across the sensor signal and sensor
ground terminals of the fuel level sensor connector
(Fig. 7 or Fig. 8). Move the float lever to the full stop
and empty stop positions shown in the resistance
chart (Fig. 7 or Fig. 8). Record the resistance at each
point. Replace the level sensor if the resistance is not
within specifications. The low fuel warning light specifications determine
if the level sensor portion of the warning light circuit
functions properly. It does not test the complete
warning light circuit. Refer to Group 8W, Wiring Diagrams for circuit
identification and Group 8E, Instrument Panel and
Gauges for fuel gauge information.
REMOVAL
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.
Fig. 6 Fuel Reservoir
14 - 18 FUEL SYSTEMS Ä

2.2L/2.5L SINGLE POINT FUEL INJECTIONÐSERVICE PROCEDURES INDEX
page page
Canister Purge Solenoid ................... 53
Electric Exhaust Gas Recirculation Transducer (EET) Service ............................... 53
Fuel Fitting ............................. 50
Fuel Injector ............................ 51
Fuel Lines and Hoses ..................... 48
Fuel Pressure Regulator ................... 51 Fuel System Pressure Release Procedure
...... 48
Heated Oxygen Sensor (O
2Sensor) .......... 54
Idle Air Control Motor ..................... 53
Manifold Absolute Pressure Sensor ........... 53
PCM Service ............................ 54
Throttle Body ............................ 48
Throttle Position Sensor ................... 52
FUEL LINES AND HOSES
Perform the Fuel System Pressure Relief Procedure
before servicing the fuel system. The procedure must
be done to bleed fuel pressure from the system before
removing clamps or hoses. Use care when removing fuel hoses to prevent dam-
age to hose or hose nipple. Always use new hose
clamps, of the correct type, during reassembly. Tighten
hose clamps to 1 N Im (10 in. lbs.) torque. Do not use
aviation style clamps on this system or hose
damage may result.
FUEL SYSTEM PRESSURE RELEASE PROCEDURE
CAUTION: Before servicing the fuel pump, fuel lines,
fuel filter, throttle body, or fuel injector, release fuel
system pressure.
(1) Loosen fuel filler cap to release fuel tank pres-
sure. (2) Disconnect injector wiring harness connector at
edge of throttle body (Fig. 1). (3) Connect a jumper wire between terminal Num-
ber 1 of the injector harness and engine ground. (4) Connect a jumper wire to the positive terminal
Number 2 of the injector harness and touch the battery
positive post for no longer than 5 seconds . This
releases system pressure. (5) Remove jumper wires.
(6) Continue fuel system service.
THROTTLE BODY
CAUTION: The fuel system is under a constant pres-
sure of 270 kPa (39 psi). When servicing the fuel
portion of the throttle body, release fuel pressure
before disconnecting any tubes. Refer to the fuel
pressure release procedure.
Always reassemble throttle body components with
new O-rings and seals where applicable. Never use
silicone lubricants on O-rings or seals, damage may
result. Use care when removing fuel tubes to prevent
damage to quick connect fittings or tube ends. Refer to Fuel Hoses, Clamps, and Quick Connect Fittings
in the Fuel Delivery Section of this Group.
REMOVAL
(1) Remove air cleaner (Fig. 2).
(2) Perform fuel system pressure release procedure.
(3) Disconnect negative battery cable.
(4) Disconnect vacuum hoses and electrical connec-
tors (Fig. 3).
Fig. 1 Injector Harness Connector
Fig. 2 Throttle Body and Air Cleaner Assembly
14 - 48 FUEL SYSTEMS Ä

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 ignition key in ON position, access
the DRBII scan tool ASD Fuel System Test to pres-
surize the fuel system. Check for leaks. (7) Reinstall air cleaner assembly.
FUEL PRESSURE REGULATOR
The fuel pressure regulator is mounted on top of
the throttle body (Fig. 6).
REMOVAL
(1) Remove air cleaner assembly.
(2) Perform Fuel System Pressure Release proce-
dure. (3) Disconnect battery negative cable.
(4) Remove pressure regulator mounting screws
(Fig. 6).
WARNING: PLACE A SHOP TOWEL AROUND FUEL
INLET CHAMBER TO CONTAIN ANY FUEL REMAIN-
ING IN THE SYSTEM.
(5) Pull pressure regulator from the throttle body.
(6) Carefully remove O-ring from pressure regula-
tor and remove gasket.
INSTALLATION
(1) Place new gasket on pressure regulator. Care-
fully install new O-ring. (2) Position pressure regulator on throttle body.
Press regulator into place and install mounting
screws. Tighten screws to 5 N Im (40 in. lbs.) torque.
(3) 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. (4) With the ignition key in ON position, access
the DRBII scan tool ASD Fuel System Test to pres-
surize the fuel system. Check for leaks. (5) Reinstall air cleaner assembly.
FUEL INJECTOR
The fuel injector is installed in the top of the throt-
tle body. The injector is covered by a cap.
REMOVAL
(1) Remove air cleaner assembly.
(2) Perform Fuel System Pressure Release proce-
dure. (3) Disconnect negative cable from battery.
(4) Remove injector cap holddown screw (Torx-
head). (5) With two small screwdrivers, lift the top off the
injector using the slots provided (Fig. 7).
(6) Using a small screwdriver placed in the hole in
the front of the electrical connector, gently pry the
injector from the pod (Fig. 8).
Fig. 6 Servicing Fuel Pressure Regulator
Fig. 7 Removing Injector Cap
Fig. 8 Removing Fuel Injector
Ä FUEL SYSTEMS 14 - 51

(7) Ensure the injector lower O-ring has been re-
moved from the pod (Fig. 9).
INSTALLATION
(1) Apply a light coating of clean engine oil on the
O-rings. (2) Place assembly in the pod. Align the injector
wiring terminals with the injector cap fastener hole
(Fig. 10).
(3) Install injector cap with locating notch aligned
with the locating lobe on the injector (Fig. 11). (4) Push down on the cap to ensure a good seal.
(5) Rotate the cap and injector to line up the at-
tachment hole (Fig. 12).
(6) Install injector cap holddown screw (torx-head
screw). Tighten screw to 4-5 N Im (35-45 in. lbs.) torque.
(7) 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. (8) With the ignition key in ON position, access
the DRBII scan tool ASD Fuel System Test to pres-
surize the fuel system. Check for leaks. (9) Reinstall the air cleaner assembly.
THROTTLE POSITION SENSOR
REMOVAL
(1) Disconnect negative cable from battery.
(2) Remove air cleaner.
(3) Disconnect harness connector from throttle po-
sition sensor (Fig. 13). (4) Remove throttle position sensor mounting
screws. (5) Remove throttle position sensor from throttle
shaft.
INSTALLATION
(1) Install throttle position sensor to throttle body,
position toward the front of the vehicle. Tighten
screws to 2 N Im (20 in. lbs.) torque.
(2) Connect 3 way connector at throttle position
sensor.
Fig. 9 Servicing Fuel Injector
Fig. 10 Fuel Injector Installation
Fig. 11 Installing Fuel Injector Cap
Fig. 12 Fuel Injector Installed
14 - 52 FUEL SYSTEMS Ä

(2) Remove sensor using Tool C-4907 (Fig. 21).
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 the same sensor is to be reinstalled, the sensor
threads must be coated with an anti-seize compound
such as Loctite 771-64 or equivalent. New sensors
are packaged with compound on the threads and do
not require additional compound. The sensor must be
tightened to 27 N Im (20 ft. lbs.) torque.
2.5L FLEXIBLE FUEL MULTI-PORT FUEL INJECTIONÐSYSTEM OPERATION
INDEX
page page
Air Conditioning (A/C) Clutch RelayÐPCM Output.61
Air Conditioning Switch SenseÐPCM Input ..... 57
Auto Shutdown (ASD) Relay and Fuel Pump RelayÐPCM Output ..................... 61
Battery VoltageÐPCM Input ................ 58
Brake SwitchÐPCM Input .................. 58
Camshaft Position SensorÐPCM Input ........ 58
CCD BUS .............................. 57
Data Link ConnectorÐPCM Output ........... 62
Duty Cycle Evap Purge SolenoidÐPCM Output . 61
Engine Coolant Temperature SensorÐPCM Input . 58
Fuel InjectorÐPCM Output ................. 62
Fuel Injectors and Fuel Rail Assembly ......... 65
Fuel Pressure Regulator ................... 65
Fuel Supply Circuit ....................... 65
General Information ....................... 55
Generator FieldÐPCM Output ............... 62
Heated Oxygen Sensor (O
2Sensor)ÐPCM Input . 59
Identifying Flexible Fuel Components .......... 55
Idle Air Control MotorÐPCM Output .......... 62 Ignition CoilÐPCM Output
.................. 62
Malfunction Indicator (Check Engine) LampÐPCM Output ............................... 62
Manifold Absolute Pressure (MAP) SensorÐPCM Input ................................ 58
Methanol Concentration SensorÐPCM Input .... 59
Modes of Operation ....................... 63
Powertrain Control Module ................. 57
Radiator Fan RelayÐPCM Output ............ 63
Speed Control SolenoidsÐPCM Output ........ 63
Speed ControlÐPCM Input ................. 60
System Diagnosis ........................ 56
System Operation ........................ 56
TachometerÐPCM Output .................. 63
Throttle Body ............................ 65
Throttle Position Sensor (TPS)ÐPCM Input ..... 60
Torque Converter Clutch SolenoidÐPCM Output . 63
Transaxle Park/Neutral SwitchÐPCM Input ..... 60
Vehicle Speed SensorÐPCM Input ........... 60
GENERAL INFORMATION
In this model year Chrysler began producing AA-
Body vehicles designed to operate on a mixture of
gasoline and methanol. These automobiles are re-
ferred to as Flexible Fuel vehicles. Fuel system com-
ponents designed for use in flexible fuel vehicles are
referred to as Methanol Compatible. Flexible fuel vehicles can operate on a mixture of
up to 85 percent methanol, 15 percent unleaded gas-
oline. These vehicles also operate on mixtures con-
taining a lower percentage of methanol or just pure
unleaded gasoline.
IDENTIFYING FLEXIBLE FUEL COMPONENTS
Flexible Fuel vehicles have unique methanol com-
patible fuel system components. Chrysler identifies
methanol compatible components that could be phys-
ically interchanged with gasoline only parts by color-
ing them green or applying a green label or tag to
them. Even though they may appear physically iden- tical, components for gasoline only AA-body vehicles
must not be used on flexible fuel vehicles.
FLEXIBLE FUEL COMPONENTS
The fuel system of flexible fuel AA-body vehicles
have the following unique methanol compatible com-
ponents.
² Duty Cycle EVAP Purge Solenoid
² Fuel pump module
² Fuel level sensor
² Fuel gauge (gauge cluster).
² Fuel tank
² Fuel pressure regulator (including O-rings)
² Fuel rail
² Fuel injectors (including O-rings)
² Fuel tubes
² Fuel filter
² EVAP canister
² Fuel filler cap
² Fuel filler tube
Fig. 21 Oxygen Sensor Socket
Ä FUEL SYSTEMS 14 - 55

METHANOL CONCENTRATION SENSORÐPCM
INPUT
The methanol concentration sensor contains a mi-
croprocessor that determines the percentage of gaso-
line and methanol in the fuel system. From the
methanol concentration sensor input, the powertrain
control module (PCM) determines the amount of
methanol in the fuel. The vehicle can operate on a
mixtures up to 85 percent methanol, 15 percent gas-
oline. The PCM supplies 8 volts to the methanol concen-
tration sensor. The methanol concentration sensor
output voltages varies with the percent of methanol
in the fuel system. The sensor output voltage (input
for PCM) ranges from 0.5 volts for pure gasoline to
4.50 volts for 85 percent methanol. For two seconds
at key ON when the operator starts the vehicle, the
sensor calibrates the PCM. During the calibration
period the sensor sends 4.45 volts to the PCM as a
correction factor. The methanol concentration sensor has a built-in
shutdown capability. If the sensor shuts down, the
PCM defaults to the previous learned value (output
voltage based on methanol percentage of fuel). The methanol concentration sensor attaches to a
bracket at the rear of the fuel tank, next to the fuel
filler tube (Fig. 6).
HEATED OXYGEN SENSOR (O2SENSOR)ÐPCM
INPUT
The heated oxygen sensor is located in the exhaust
manifold. The sensor provides an input voltage to the
PCM (Fig. 7). The input tells the PCM the oxygen
content of the exhaust gas. The PCM uses this infor-
mation to fine tune the air-fuel ratio by adjusting in-
jector pulse width. Flexible fuel vehicles operate on mixtures of fuel
that contain up to 85 percent methanol and 15 per-
cent unleaded gasoline. Different percentages of
methanol in the fuel require different air/fuel ratios. The methanol concentration sensor inputs tells the
PCM what percentage of methanol is in the fuel. The
PCM calculates the ideal air/fuel ratio from the
methanol concentration sensor input. The heated ox-
ygen sensor input tells the PCM if it has reached the
desired air/fuel ratio.
The O
2sensor produces voltages from 0 to 1 volt,
depending upon the oxygen content of the exhaust
gas in the exhaust manifold. When a large amount of
oxygen is present (caused by a lean air-fuel mixture),
the sensor produces a low voltage. When there is a
lesser amount present (rich air-fuel mixture) it pro-
duces a higher voltage. By monitoring the oxygen
content and converting it to electrical voltage, the
sensor acts as a rich-lean switch. The oxygen sensor is equipped with a heating ele-
ment that keeps the sensor at proper operating tem-
perature during all operating modes. Maintaining
correct sensor temperature at all times allows the
system to enter into closed loop operation sooner.
Also, it allows the system to remain in closed loop
operation during periods of extended idle.
Fig. 5 Manifold Absolute Pressure (MAP) SensorFig. 6 Methanol Concentration Sensor
Fig. 7 Heated Oxygen Sensor
Ä FUEL SYSTEMS 14 - 59

2.5L FLEXIBLE FUEL MULTI-PORT FUEL INJECTIONÐSERVICE PROCEDURES INDEX
page page
Fuel Injector ............................. 80
Fuel Injector Rail Assembly ................. 79
Fuel Pressure Regulator .................... 81
Fuel System Pressure Release Procedure ...... 78
General Information ....................... 77
Heated Oxygen Sensor (O
2Sensor) ........... 82
Identifying Flexible Fuel Components .......... 77
Idle Air Control Motor ...................... 78 Manifold Absolute Pressure (MAP) Sensor
Service ............................... 82
Methanol Concentration Sensor .............. 82
PCM Service ............................ 82
Service Precautions for Flexible Fuel Vehicles .... 77
Throttle Body ............................ 77
Throttle Body Removal ..................... 79
Throttle Position Sensor (TPS) ............... 78
GENERAL INFORMATION
In this model year Chrysler began producing AA-
Body vehicles designed to operate on a mixture of
gasoline and methanol. These automobiles are referred
to as Flexible Fuel vehicles. Fuel system components
designed for use in flexible fuel vehicles are referred to
as Methanol Compatible. Flexible fuel vehicles can operate on a mixture of up
to 85 percent methanol, 15 percent unleaded gasoline.
These vehicles also operate on mixtures containing a
lower percentage of methanol or just pure unleaded
gasoline.
SERVICE PRECAUTIONS FOR FLEXIBLE FUEL
VEHICLES
Methanol is more toxic than gasoline. Always release
fuel system pressure before servicing fuel system com-
ponents and wear methanol resistant gloves and eye
protection. Avoid breathing methanol vapors or ingesting
methanol. Headaches, dizziness and even unconscious-
ness could result from breathing these vapors. Serious
injury, blindness and even death could result from
ingesting methanol. Methanol vapors are extremely flammable and can
travel along the ground. Service vehicles in well ven-
tilated areas and avoid ignition sources. Never smoke
while servicing the vehicle. Do not allow methanol to contact skin. Prolonged
contact with methanol can cause dry skin or an allergic
skin reaction. Also, prolonged contact could result in
absorption through the skin.
IDENTIFYING FLEXIBLE FUEL COMPONENTS
Flexible Fuel vehicles have unique methanol compat-
ible fuel system components. Chrysler identifies methanol
compatible components that could be physically inter-
changed with gasoline only parts by coloring them green
or applying a green label or tag to them. Even though
they may appear physically identical, components
for gasoline only AA-body vehicles must not be used
on flexible fuel vehicles.
FLEXIBLE FUEL COMPONENTS
The fuel system of flexible fuel AA-body vehicles have
the following unique methanol compatible components.
² Duty cycle EVAP purge solenoid
² EVAP canister
² Fuel pump module
² Fuel level sensor
² Fuel gauge (gauge cluster).
² Fuel tank
² Fuel pressure regulator (including O-rings)
² Fuel rail
² Fuel injectors (including O-rings)
² Fuel tubes
² Fuel filter
² Fuel filler cap
² Fuel filler tube
² Methanol concentration sensor
² Pressure relief/rollover valve
² PCV Valve
² All fuel system and emission system hoses and tubes
THROTTLE BODY
WARNING: THROTTLE BODIES DESIGNED FOR
GASOLINE ONLY VEHICLES CANNOT BE USED ON
FLEXIBLE FUEL AA-BODY VEHICLES. WHEN RE-
PLACING THE THROTTLE BODY OF A FLEXIBLE
FUEL VEHICLE, ONLY USE AN ORIGINAL EQUIP-
MENT REPLACEMENT.
When servicing throttle body components, always
reassemble components with new O-rings and seals
where applicable. Never use lubricants on O-rings or
seals, damage may result. If assembly of component is
difficult, use water to aid assembly. Use care when
removing hoses to prevent damage to hose or hose
nipple.
Ä FUEL SYSTEMS 14 - 77

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