fuel cap release CHEVROLET DYNASTY 1993 Service Manual

tifreeze to achieve adequate protection. A mix table
on the coolant container indicates the amount of an-
tifreeze required to winterize the cooling system
based on the capacity, see Capacity Chart in General
Information section of this group.
SELECTING ANTIFREEZE
Chrysler Corporation recommends Mopar Anti-
freeze/Summer Coolant, or equivalent be used to win-
terize and protect cooling system.
RADIATOR CAP
The radiator cap must be secure to provide proper
pressure release and coolant recovery. Inspect and
test radiator cap when cooling system service is per-
formed or when problem is suspected.
COOLING SYSTEM SERVICE
The cooling system should be drained, flushed and
filled with the proper coolant mixture at the inter-
vals described in the Lubrication and Maintenance
Schedules. Refer to General Information section of
this group. For proper service instructions see Group
7, Cooling System.
ENGINE AIR CLEANER
The engine air cleaner should be serviced at the in-
tervals described in the Lubrication and Mainte-
nance Schedules. Refer to General Information
section of this group. Additional information can be
found in Group 14, Fuel System and Group 25, Emis-
sion System. Inspect all air cleaner hoses or tubes for
damage or leaks when other engine compartment
service is performed. Replace faulty components.
AIR CLEANER SERVICE
CAUTION: The air cleaner cover must be installed
properly for the emissions system and engine con-
troller to function correctly. Do not immerse paper air filter element or temper-
ature sensor in cleaning solvents, damage can re-
sult.
TO SERVICE AIR CLEANER ASSEMBLY: (1) Raise hood of vehicle and inspect all air cleaner
components for damage or improper attachment. (2) Remove air cleaner cover (Fig. 6, 7, 8, 9, or 10).
(3) Remove paper air filter element from air
cleaner body. Hold a shop light on throttle body side
of element. Inspect air intake side of element. If light
is visible through element, blow dust from element
(Fig. 11) and reuse. If element is saturated with oil
or light is not visible, replace filter. If element is sat-
urated with oil, perform crankcase ventilation sys-
tem tests. (4) Remove fiber crankcase filter (Fig. 6, 7, 8, 9, or
10) and clean with solvent, squeeze filter dry and ap- ply small amount of engine oil. If a metallic mesh is
used to retain fiber filter, clean mesh with solvent
and reuse.
(5) Clean inside of air cleaner cover and body with
vacuum or compressed air. If oily, wash with solvent. To Install, reverse the preceding operation.
Fig. 6 Air CleanerÐ3.0L Engine
Fig. 7 Air CleanerÐFlexible Fuel Engine
Fig. 8 Air CleanerÐ16 Valve Engine
Ä LUBRICATION AND MAINTENANCE 0 - 11

When testing secondary cables for punctures and
cracks with an oscilloscope follow the equipment
manufacturers instructions. If an oscilloscope is not available, secondary cables
can be tested as follows:
CAUTION: Do not leave any one spark plug cable
disconnected any longer than necessary during test-
ing. Excessive heat could damage the catalytic con-
verter. Total test time must not exceed ten minutes.
(a) With the engine not running, connect one end
of a test probe to a good ground. Use a probe made of
insulated wire with insulated alligator clips on each
end. (b) With engine running, move test probe along
entire length of all cables (approximately 0 to 1/8
inch gap). If punctures or cracks are present there
will be a noticeable spark jump from the faulty area
to the probe. Check the coil cable the same way.
Replace cracked, leaking or faulty cables.
When replacing cables, install the new high
tension cable and nipple assembly over cap or
coil tower. When entering the terminal into the
tower, push lightly, then pinch the large diam-
eter of nipple to release air trapped between the
nipple and tower. Continue pushing on the cable
and nipple until cables are properly seated in the
cap towers. A snap should be heard as terminal
goes into place. Use the same procedure to install cable in coil tower.
Wipe the spark plug insulator clean before reinstalling
cable and cover. Use the following procedure when removing the high
tension cable from the spark plug. First, remove the
cable from the retaining bracket. Then grasp the ter-
minal as close as possible to the spark plug. Rotate the
cover and pull the cable straight back. Pulling on the
cable itself will damage the conductor and termi-
nal connection. Do not use pliers and do not pull
the cable at an angle. Doing so will damage the
insulation, cable terminal or the spark plug in-
sulator. Wipe spark plug insulator clean before
reinstalling cable and cover. Resistance type cable is identified by the words
Electronic Suppression printed on the cable jacket.
Use an ohmmeter to check resistance type cable for
open circuits, loose terminals or high resistance as
follows: (a) Remove cable from spark plug.
(b) Lift distributor cap from distributor with
cables intact. Do not remove cables from cap. The
cables must be removed from the spark plugs. (c) Connect the ohmmeter between spark plug end
terminal and the corresponding electrode inside the
cap, make sure ohmmeter probes are in good contact.
Resistance should be within tolerance shown in the cable resistance chart. If resistance is
not within tolerance, remove cable at cap tower
and check the cable. If resistance is still not within
tolerance, replace cable assembly. Test all spark
plug cables in same manner.
To test coil to distributor cap high tension cable,
remove distributor cap with the cable intact. Do not
remove cable from the cap. Connect the ohmmeter
between center contact in the cap and remove the ca-
ble at coil tower and check cable resistance. If resis-
tance is not within tolerance, replace the cable.
SPARK PLUGS
Resistor spark plugs are used in all engines and
have resistance values of 6,000 to 20,000 ohms when
checked with at least a 1000 volt tester. Remove the spark plugs and examine them for
burned electrodes and fouled, cracked or broken por-
celain insulators. Keep plugs arranged in the order
in which they were removed from the engine. An iso-
lated plug displaying an abnormal condition indi-
cates that a problem exists in the corresponding
cylinder. Replace spark plugs at the intervals recom-
mended in Group O. Undamaged low milage spark plugs can be cleaned
and reused. Refer to the Spark Plug Condition sec-
tion of this group. After cleaning, file the center elec-
trode flat with a small point file or jewelers file.
Adjust the gap between the electrodes (Fig. 6) to the
dimensions specified in the chart at the end of this
section. Always tighten spark plugs to the specified torque.
Over tightening can cause distortion and change
spark plug gap. Tighten spark plugs to 28 N Im (20 ft.
lbs.) torque.
SPARK PLUG CONDITION
NORMAL OPERATING CONDITIONS
The few deposits present will be probably light tan
or slightly gray in color with most grades of commer-
cial gasoline (Fig. 7). There will not be evidence of
electrode burning. Gap growth will not average more
than approximately 0.025 mm (.001 in) per 1600 km
(1000 miles) of operation. Spark plugs that have nor-
mal wear can usually be cleaned, have the electrodes
filed and regapped, and then reinstalled. Some fuel refiners in several areas of the United
States have introduced a manganese additive (MMT)
CABLE RESISTANCE CHART
Ä IGNITION SYSTEMS 8D - 3

valve spring retainer locks to become dislocated
when depressing the valve spring. Check and make
sure the locks are in their proper location. (3) Install valve cover as previously outlined in
this section.
VALVE SPRINGS AND VALVE STEM SEALS
REMOVAL
(1) Remove rocker arms as previously outlined in
this section. (2) Rotate crankshaft until piston is at TDC on
compression. (3) With air hose attached to adapter tool installed
in spark plug hole, apply 90-120 psi air pressure. (4) Using Special Tool C-4682 (Fig. 12) compress
valve springs and remove valve locks. (5) Remove valve spring.
(6) Remove valve stem seal by gently prying side-
to-side with a screwdriver blade. Once dislodged from
guide post, seal may be easily removed.
INSTALLATION
CAUTION: Flexible Fuel Vehicle Valve use unique
valve stem oil seals they are green in color. Stan-
dard valve stem oil seals are NOT to be interchanged
with Flexible Fuel Vehicles engines.
(1) Install valve seals (Fig. 13) as outlined in step
(2) of Valve Gear Reassembly - After Valve Ser-
vice in this section.
(2) Using Special Tool C-4682 compress valve
springs only enough to install locks. Correct align-
ment of tool is necessary to avoid nicking valve
stems (air pressure required), piston at TDC. (3) Install rocker arms as previously outlined in
this section.
CYLINDER HEAD
REMOVAL
(1) Perform fuel system pressure release procedure
before attempting any repairs. Refer to Fuel Sys-
tem Group 14 (2) Disconnect negative battery cable. Drain cool-
ing system. Refer to Cooling System, Group 7. (3) Remove air cleaner and disconnect all vacuum
lines, electrical wiring and fuel lines from throttle
body. (4) Remove throttle linkage.
(5) Loosen power steering pump and remove belt.
(6) Remove power brake vacuum hose from intake
manifold. (7) Remove water hoses from water crossover.
(8) Raise vehicle and remove exhaust pipe from
manifold. (9) Remove power steering pump assembly and set
aside. (10) Disconnect coil wiring connector and coil wire
from coil. (11) Disconnect dipstick tube from thermostat
housing and ROTATEbracket from stud. DO NOT
bend the bracket or tube. (12) See Solid Mount Compressor Bracket in
STANDARD SERVICE PROCEDURES, this Group. (13) Remove cylinder head bolts.
INSPECT HEAD AND CAMSHAFT BEARINGJOURNALS
(1) Cylinder head must be flat within 0.1mm (.004
inch) (Fig. 14). (2) Inspect camshaft journals for scoring and jour-
nal caps for oversize markings. When servicing cyl-
inder head or camshaft, it is necessary to be certain
that oversized camshafts are used only in oversized
heads. Identify oversize components as follows:
Fig. 12 Removing and Installing Valve SpringFig. 13 Valve Stem Seals
9 - 26 2.2/2.5L ENGINE Ä

for diagnostic and service procedures on the air control
valve and temperature sensor located in the air
cleaner.
INTAKE AND EXHAUST MANIFOLDS SERVICEÐTBI
ENGINE
Intake and exhaust manifolds use a one piece gasket.
Service procedures requiring removal and installation
( of either ) must include both manifolds.
FUEL SYSTEM PRESSURE RELEASE PROCE- DURE
The Fuel System is under a constant pressure
of at least 265 kPa (39 psi). Before servicing the
fuel pump, fuel lines, fuel filter, throttle body or
fuel injector, the fuel system pressure must be
released. (a) Loosen fuel filler cap to release fuel tank pres-
sure. (b) Disconnect injector wiring harness from engine
harness. (c) Connect a jumper wire to ground terminal
Number 1 of the injector harness (Fig. 2) to engine
ground. (d) Connect a jumper wire to the positive terminal
Number 2 of the injector harness (Fig. 2) and touch
the battery positive post for no longer than 5 seconds.
This releases system pressure. (e) Remove jumper wires.
(f) Continue fuel system service.
REMOVAL
(1) Perform fuel system pressure release procedure
before attempting any repairs. (2) Disconnect negative battery cable. Drain cool-
ing system. Refer to Cooling System, Group 7 for pro-
cedure. (3) Remove air cleaner and disconnect all vacuum
lines, electrical wiring and fuel lines from throttle
body. (4) Remove throttle linkage.
(5) Loosen power steering pump and remove belt.
(6) Remove power brake vacuum hose from intake
manifold. (7) Disconnect EGR tube from intake manifold and
remove water hoses from water crossover. (8) Raise vehicle and remove exhaust pipe from
manifold. (9) Remove power steering pump assembly and set
aside. (10) Remove intake manifold retaining screws
(Fig. 3). (11) Lower vehicle and remove intake manifold.
(12) Remove exhaust manifold retaining nuts (Fig.
3). (13) Remove exhaust manifold.
Fig. 2 Injector Harness Connector
Fig. 3 Intake and Exhaust Manifold Attaching PointsÐ2.2/2.5L Engines
Fig. 1 Air HeaterÐTBI Engine
11 - 6 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä

CLEANING AND INSPECTION
(1) Discard gaskets and clean all gasket surfaces
on both manifolds and on cylinder head. (2) Test gasket surfaces of manifolds for flatness
with a straight edge. Surfaces must be flat within
0.15mm per 300mm (.006 in. per foot) of manifold
length. (3) Inspect manifolds for cracks and distortion.
INSTALLATION
(1) Install a new intake and exhaust manifold gas-
ket. Coat steel gasket lightly with Gasket Sealer on
manifold side. Do notcoat composition gasket with
(any) sealer. (2) Set exhaust manifold in place. Tighten retain-
ing nuts starting at center and progressing outward
in both directions to 23 N Im (200 in. lbs.) torque. Re-
peat this procedure until all nuts are at specified
torque. (3) Set intake manifold in place.
(4) Raise vehicle and tighten retaining screws
starting at center and progressing outward in both
directions to 23 N Im (200 in. lbs.) torque (Fig. 3). Re-
peat this procedure until all screws are at specified
torque. (5) Reverse removal procedures 1-9 for installation.
(6) With the DRBII Scan Tool use ASD Fuel Sys-
tem Test to pressurize system to check for leaks.
CAUTION: When using the ASD Fuel System Test,
the Auto Shutdown (ASD) relay will remain ener-
gized for 7 minutes or until the ignition switch is
turned to the OFF position, or Stop All Test is se-
lected.
INTAKE AND EXHAUST MANIFOLDSÐFLEXIBLE
FUEL ENGINE
INTAKE MANIFOLD
The manifold is die-cast aluminum with upper ple-
num and 4 tubes lower runners. These attach to the
cylinder head, with each runner leading directly to a
cylinder. The manifold is also machined for fuel rail attach-
ment and injector installation. The throttle body is
installed on the upper plenum of the manifold.
EXHAUST MANIFOLD
All high strength iron casting that intermesh with
the intake manifold. For standard engines a four
branch design collects and directs exhaust gases to
the conical (articulated joint connection) outlet.
INTAKE/EXHAUST MANIFOLDS
SERVICEÐFLEXIBLE FUEL ENGINES
Intake and exhaust manifolds use a one piece gas-
ket. Service procedures requiring removal and instal-
lation of either must include both manifolds.
SERVICE PRECAUTIONS
Methanol is more toxic than gasoline. Always re-
lease fuel system pressure before servicing fuel sys-
tem components and wear methanol resistant gloves
and eye protection. Avoid breathing methanol vapors or ingesting
methanol. Headaches, dizziness and even uncon-
sciousness 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 al-
lergic skin reaction. Also, prolonged contact could re-
sult in absorption through the skin.
FUEL SYSTEM PRESSURE RELEASE PROCEDURE
WARNING: RELEASE FUEL SYSTEM PRESSURE
BEFORE SERVICING FUEL SYSTEM COMPONENTS.
WEAR METHANOL RESISTANT GLOVES AND EYE
PROTECTION WHILE SERVICING THE FUEL SYS-
TEM.
(a) Disconnect negative cable from battery.
(b) Remove fuel filler cap.
(c) Remove the protective cap from the fuel pres-
sure test port on the fuel rail (Fig. 4).
(d) Place the open end of fuel pressure release
hose, tool number C-4799-1, into an approved gas-
oline container. Connect the other end of hose
C-4799-1 to the fuel pressure test port (Fig. 5).
Fuel pressure will bleed off through the hose into
the gasoline container. Fuel gauge C-4799-A con-
tains hose C-4799-1.
Fig. 4 Fuel Pressure Test Port
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 7

The exhaust manifolds are made of ductile cast
iron with the front bank and rear bank independent
of each other. The exhaust from the front bank ex-
haust manifold is led through on exhaust crossover
pipe to be combined with the rear bank exhaust at
the exhaust outlet to the exhaust pipe (Fig. 2).
INTAKE PLENUM/MANIFOLD
REMOVAL
(1) Perform fuel system pressure release procedure
(before attempting any repairs). (2) Disconnect negative battery cable. Drain cooling
system. See Cooling System, Group 7. (3) Remove air cleaner to throttle body hose (Fig. 3).
FUEL SYSTEM PRESSURE RELEASE PROCE-DURE
The MPI fuel system is under a constant pres-
sure of about 330 kPa (48 psi). Before servicing
the fuel pump, fuel lines, fuel filter, throttle body
or fuel injector, the fuel system pressure must be
released .
(a) Loosen fuel filler cap to release fuel tank pres-
sure. (b) Disconnect injector wiring harness from engine
harness. (c) Connect a jumper wire to ground terminal
Number 1 of the injector harness (Fig. 1) to engine
ground. (d) Connect a jumper wire to the positive terminal
Number 2 of the injector harness (Fig. 1) and touch
the battery positive post for no longer than 5 seconds.
This releases system pressure.
Fig. 1 Injector Harness Connector
Fig. 2 Intake and Exhaust ManifoldsÐ 3.0L Engine
11 - 14 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä

(2) Attach exhaust pipe to exhaust manifold and
tighten shoulder bolt to 28 N Im (250 in. lbs.)
(3) Attach crossover pipe to exhaust manifold and
tighten bolt to 69 N Im (51 ft. lbs.)
(4) Connect heated oxygen sensor lead (Fig. 18).
(5) Install front exhaust manifold and attach ex-
haust crossover. (6) Install front manifold heat shield and tighten
attaching screws to 15 N Im (130 in. lbs.) (Fig. 2).
INTAKE/EXHAUST MANIFOLD SERVICEÐ3.3/3.8L
ENGINES
INTAKE MANIFOLD
REMOVAL
(1) Perform fuel system pressure release procedure,
Before attempting any repairs. (2) Disconnect negative battery cable. Drain cool-
ing system. Refer to Cooling System, Group 7.
FUEL SYSTEM PRESSURE RELEASE PROCE- DURE
The MPI fuel system is under a constant pressure
of about 330 kPa (48 psi). Before servicing the fuel
pump, fuel lines, fuel filter, throttle body or fuel
injector, the fuel system pressure must be released.
(a) Loosen fuel filler cap to release fuel tank pres-
sure. (b) Disconnect injector wiring harness from engine
harness.
(c) Connect a jumper wire to ground terminal Num-
ber 1 of the injector harness (Fig. 1) to engine ground.
(d) Connect a jumper wire to the positive terminal
Number 2 of the injector harness (Fig. 1) and touch
the battery positive post for no longer than 5 seconds.
This releases system pressure. (e) Remove jumper wires.
(f) Continue fuel system service.
(3) Remove air cleaner to throttle body hose assem-
bly (Fig. 2).
Fig. 20 Check Exhaust Manifold Mounting Surface
Fig. 21 Identify Exhaust Manifold Gaskets
Fig. 1 Injector Harness Connectors
Fig. 2 Throttle Body AssemblyÐ3.3/3.8L Engines
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 19

FUEL DELIVERY SYSTEM INDEX
page page
Chassis Fuel Tubes ...................... 11
Flexible Fuel Components ................... 3
Fuel FilterÐAll Vehicles .................... 9
Fuel Hoses, Clamps, and Quick Connect Fittings . 10
Fuel Pump Assembly ...................... 5
Fuel Pump Module Installation ............... 9
Fuel Pump Module Removal ................. 8
Fuel Pump Pressure TestÐ2.2L/2.5L TBI and 3.0L MPI Engines ........................... 7
Fuel Pump Pressure TestÐAll Except 2.2L/2.5L TBI and 3.0L MPI ....................... 6
Fuel Pump Strainer Service .................. 9 Fuel System Pressure
...................... 6
Fuel System Pressure Release ProcedureÐ 2.2L/2.5L TBI ........................... 4
Fuel System Pressure Release ProcedureÐ3.0L . . 5
Fuel System Pressure Release ProcedureÐExcept 2.2L/2.5L TBI and 3.0L ................... 4
General Information ........................ 3
Identifying Flexible Fuel Components .......... 3
Mechanical Malfunctions .................... 8
Methanol Concentration SensorÐFlexible Fuel AA-Body .............................. 4
Service Precautions for Flexible Fuel Vehicles .... 3
GENERAL INFORMATION
Beginning this model year, Chrysler began produc-
ing AA-Body vehicles designed to operate on a mix-
ture of gasoline and methanol. These automobiles are
referred to as Flexible Fuel vehicles. 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. In many cases, the procedures for servicing flexible
fuel components is identical to gasoline only compo-
nents. Refer to the particular Service Procedure in
this section. If the service procedure for flexible fuel
component differs from a gasoline only component,
the title of each service procedure identifies the ap-
plication.
SERVICE PRECAUTIONS FOR FLEXIBLE FUEL
VEHICLES
Methanol is more toxic than gasoline. Always re-
lease fuel system pressure before servicing fuel sys-
tem components and wear methanol resistant gloves
and eye protection. Avoid breathing methanol vapors or ingesting
methanol. Headaches, dizziness and even uncon-
sciousness 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 al-
lergic skin reaction. Also, prolonged contact could re-
sult in absorption through the skin.
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 vehicles must not
be used on flexible fuel vehicles.
FLEXIBLE FUEL COMPONENTS
Flexible fuel AA-body vehicles uses many unique
fuel system components. The unique parts are green
in appearance or have a green tag or label attached
to them. While components used on gasoline only ve-
hicles may look similar or identical, they cannot be
used on flexible fuel vehicles. When servicing a com-
ponent, always use an original equipment or equiva-
lent flexible fuel replacement. The fuel system of flexible fuel AA-body vehicles
have the following unique components.
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
² Pressure relief/Rollover valve
² All fuel system and emission system hoses and
tubes
Ä FUEL SYSTEMS 14 - 3

INSTRUMENT PANEL CLUSTER IDENTIFICATIONÐFLEXIBLE FUEL AA-BODY
Flexible fuel A-Body vehicles use a unique gauge
cluster. To identify the cluster, remove it from the
instrument panel and check the number on the tag
on the top. If the part number matches the number
in the parts book for flexible fuel A-bodies, the vehi-
cle was built with the correct cluster. Refer to Group
8E, Instrument Panel and Gauges, for cluster re-
moval and installation.
METHANOL CONCENTRATION SENSORÐFLEXIBLE
FUEL AA-BODY
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 methanol concentration sensor output voltages
varies with the percent of methanol in the fuel sys-
tem. The sensor output voltage (input for PCM)
ranges from 0.5 volts for pure gasoline to 4.75 volts
for 85 percent methanol. For two seconds at key ON
when the operator starts the vehicle, the sensor cal-
ibrates 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, it de-
faults 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. 1).
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.
Quick connect fittings attach the fuel tubes to the
methanol concentration sensor (Fig. 1) (1) Release fuel system pressure. Refer to the Fuel
System Pressure Release Procedure. (2) Disconnect the fuel tubes from sensor. Refer to
Quick Connect Fittings in this section. (3) Disconnect electrical connector from sensor.
(4) Remove mounting nuts.
INSTALLATION
(1) Place sensor on bracket. Tighten mounting nut.
(2) Attach electrical connector to sensor.
(3) Connect fuel tubes to sensor. Refer to Quick
Connect Fittings in this section.
FUEL SYSTEM PRESSURE RELEASE
PROCEDUREÐEXCEPT 2.2L/2.5L TBI AND 3.0L
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 an approved gaso-
line container or a container approved for gasoline/
methanol 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 gas-
oline container. Fuel gauge C-4799-A contains hose
C-4799-1.
FUEL SYSTEM PRESSURE RELEASE
PROCEDUREÐ2.2L/2.5L TBI
CAUTION: Before servicing the fuel pump, fuel
lines, fuel filter, throttle body, or fuel injector, re-
lease fuel system pressure.Fig. 1 Methanol Concentration Sensor
14 - 4 FUEL SYSTEMS Ä

(1) Loosen fuel filler cap to release fuel tank pres-
sure. (2) Disconnect injector wiring harness connector at
edge of throttle body (Fig. 4). (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 bat-
tery positive post for no longer than 5 seconds .
This releases system pressure. (5) Remove jumper wires.
(6) Continue fuel system service.
FUEL SYSTEM PRESSURE RELEASE
PROCEDUREÐ3.0L
(1) Disconnect the fuel rail electrical harness from
the engine harness. Refer to Group 8W, Wiring Dia-
grams. (2) Connect one end of a jumper wire to the A142
circuit terminal of the fuel rail harness connector. (3) Connect the other end of the jumper wire to a
12 volt power source. (4) Connect one end of a jumper wire to a good
ground source. (5) Momentarily ground one of the injectors by
connecting the other end of the jumper wire to an in-
jector terminal in the harness connector. Repeat pro-
cedure for 2 to 3 injectors.
FUEL PUMP ASSEMBLY
The fuel pump assembly consists of the fuel pump
and the reservoir body. The reservoir body takes the place of an internal
fuel tank reservoir. The reservoir maintains fuel at
the pump inlet during all driving conditions, espe-
cially when the fuel level is low. The system uses a positive displacement, gerotor
gear, immersible pump with a permanent magnet
electric motor (Fig. 5). The pump draws fuel through
a strainer and pushes it through the electric motor to
the outlet. The pump contains three check valves.
One valve relieves internal fuel pump pressure and
regulates maximum pump output. Another valve, in-
side the pump assembly in the fuel return circuit,
prevents fuel tank leakage if the line is damaged
during an accident. The third valve, in the pump out-
let, maintains pump pressure during engine off con-
ditions. The fuel pump relay provides voltage to the
fuel pump. All pumps have a maximum stall pres-
sure output of approximately 930 kPa (135 psi). All front wheel drive car fuel systems, except
Turbo III and flexible fuel AA-body vehicles use the
same fuel pump. Turbo III and flexible fuel AA-Body
vehicles each use different fuel pumps although they
look similar to pumps used in other vehicles. Release fuel system pressure before servicing the
fuel tank, fuel pump, fuel lines, fuel filter, or parts of
the fuel rail. Follow the Fuel System Pressure Re-
lease procedure to relieve fuel system pressure.
Fig. 2 Fuel Pressure Test PortÐTypical
Fig. 3 Releasing Fuel PressureÐEngines With Test Ports On Fuel Rail
Fig. 4 Injector Harness ConnectorÐ2.2L/2.5L TBI
Ä FUEL SYSTEMS 14 - 5