(1) Disconnect negative battery cable.
(2) Remove the fuel filler cap. Using an approved
portable gasoline siphon/storage tank, drain fuel
tank.
(3) Raise and support vehicle.
(4) Using a small straight blade screwdriver, pull
back the stems of the push clips that secure the fuel
filler neck shroud (located at bottom of left rear
wheel well) in place (Fig. 4). This unlocks the push
clip allowing them to be removed by pulling assembly
out of shroud. Remove shroud.
(5) Disconnect fuel fill hose and fill vent hose from
filler neck (Fig. 5).
WARNING: WRAP SHOP TOWELS AROUND FUEL
HOSES TO ABSORB ANY FUEL SPILLAGE DURING
FUEL TANK REMOVAL.
(6) Disconnect fuel tank vent hose from vent tube.
Disconnect fuel supply and return hoses from tubes
(Fig. 6).
The fuel tank and skid plate are removed as an as-
sembly.(7) Centrally position a transmission jack under
skid plate/fuel tank assembly.
(8) Remove skid plate/fuel tank assembly mounting
nuts (Fig. 7).Do not loosen tank strap nuts.
(9) Lower the skid plate/fuel tank assembly
slightly and disconnect the gauge sender wire con-
nector.
(10) Lower the fuel tank on transmission jack.
(11) Remove tank strap nuts to remove tank from
skid plate.
INSTALLATIONÐYJ MODELS
(1) Place tank into skid plate. Wrap straps around
tank with strap bolts inserted through holes in skid
plate. Tighten strap nuts to 7.3 Nzm (65 in. lbs.)
torque.
Fig. 4 Fuel Filler Neck ShroudÐYJ Models
Fig. 5 Filler Neck HosesÐYJ Models
Fig. 6 Fuel Tank HosesÐYJ Models
Fig. 7 Fuel TankÐRemove/InstallÐYJ Models
JFUEL TANKS 14 - 15
(2) Raise skid plate/fuel tank until gauge sender
wire connector can be connected to harness connec-
tor.
(3) Finish raising skid plate/fuel tank assembly
into position. Tighten mounting nuts to 16 Nzm (12
ft. lbs.) torque. Remove transmission jack.
(4) Connect fuel fill hose and fill vent hose to filler
neck. Tighten hose clamps.
(5) Connect vent hose to vent tube.
(6) Connect fuel supply hose to the supply tube
and fuel return hose to return tube. Tighten hose
clamps.
(7) Install fuel filler neck shroud with push clips.
(8) Lower vehicle.
(9) Fill fuel tank. Install filler cap.
(10) Connect negative battery cable to battery.
(11) Start vehicle and inspect for leaks.
FUEL GAUGE SENDING UNIT
The fuel gauge sending unit is attached to the fuel
pump module. Refer to Fuel Pump Module in the
Fuel Delivery System section of this group.
FUEL TANK PRESSURE RELIEF/ROLLOVER VALVE
The fuel tank is equipped with a pressure relief/
rollover valve (Fig. 8). The dual function valve will
relieve fuel tank pressure and prevent fuel flow
through the fuel tank vent tubes in the event of ac-
cidental vehicle rollover.
The valve consists of a plunger, spring and orifice/
guide plate (Fig. 9). The valve is normally open al-
lowing fuel vapor to vent to the EVAP canister. Here
it is stored until it can be consumed by the engine
(under controlled conditions). The plunger seats inthe guide plate at the orifice preventing liquid fuel
from reaching the EVAP canister. This is done if bot-
tom of plunger is contacted by fuel sloshing in tank
when vehicle is cornering.
In the event of accidental vehicle rollover, the valve
is inverted. In this position the plunger is forced
against the guide plate and raw fuel is prevented
from flowing through the valve orifice into the fuel
tank vent tube.
REMOVAL
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE (EVEN WITH THE ENGINE OFF).
BEFORE SERVICING THE PRESSURE RELIEF/
ROLLOVER VALVE, THE FUEL SYSTEM PRESSURE
MUST BE RELEASED. REFER TO THE FUEL PRES-
SURE RELEASE PROCEDURE IN THIS GROUP.
(1) Disconnect negative battery cable.
(2) Remove the fuel filler cap and drain fuel tank.
Refer to Fuel Tank Removal.
(3) Remove fuel tank. Refer to Fuel Tank Removal.
(4) The rollover valve is seated in a grommet. Re-
move by prying one side upward and then roll the
grommet out of tank (Fig. 8).
INSTALLATION
(1) Start one side of grommet into opening in fuel
tank. Using finger pressure only, press valve/grom-
met into place.
(2) Install fuel tank. Refer to Fuel Tank Installa-
tion.
(3) Fill fuel tank. Install fuel tank filler cap.
(4) Connect negative battery cable.
(5) Start vehicle and check for leaks.
Fig. 8 Valve LocationÐTypical
Fig. 9 Pressure Relief/Rollover Valve Operation
14 - 16 FUEL TANKSJ
MULTI-PORT FUEL INJECTION (MFI)ÐCOMPONENT REMOVAL/INSTALLATION
INDEX
page page
Accelerator Pedal and Throttle Cable........... 58
Air Cleaner Element....................... 59
Air Cleaner Housing....................... 58
Air Conditioning (A/C) Clutch Relay............ 58
Automatic Shutdown (ASD) Relay............. 59
Brake Switch............................ 59
Camshaft Position Sensor................... 60
Crankshaft Position Sensor.................. 60
Engine Coolant Temperature Sensor........... 60
Fuel Filter............................... 60
Fuel Injector............................. 60
Fuel Pressure Regulator.................... 61
Fuel Pump Module........................ 61
Fuel Pump Relay......................... 61
Fuel Rail Assembly........................ 62
Fuel System Pressure Release Procedure....... 62
Fuel Tank Pressure Relief/Rollover Valve........ 62Fuel Tanks.............................. 62
Fuel Tubes/Lines/Hoses and Clamps........... 62
Idle Air Control (IAC) Motor.................. 62
Ignition Coil............................. 62
Intake Manifold........................... 63
Intake Manifold Air Temperature Sensor......... 60
Manifold Absolute Pressure (Map) Sensor....... 63
Oxygen (O2S) Sensor...................... 63
Park Neutral Switch....................... 63
Power Steering Pressure SwitchÐ2.5L
Engine Only............................ 63
Powertrain Control Module (PCM)............. 64
Quick-Connect Fittings..................... 64
Throttle Body............................ 64
Throttle Position Sensor (TPS)............... 65
Torque Converter Clutch Relay............... 65
Vehicle Speed Sensor...................... 66
ACCELERATOR PEDAL AND THROTTLE CABLE
Refer to the Accelerator Pedal and Throttle Cable
section of this group for removal/installation proce-
dures.
AIR CONDITIONING (A/C) CLUTCH RELAY
The A/C clutch relay is located in the power distri-
bution center (PDC) (Figs. 1 or 2). For location of this
relay within the PDC, refer to label on PDC cover.
AIR CLEANER HOUSING
REMOVAL
(1) Unlock clean air hose clamp (Figs. 3 or 4) at air
cleaner cover. To unlock the clamp, attach adjustablepliers to clamp and rotate pliers as shown in figure
5. Remove clean air hose at cover.
(2) Disconnect vacuum lines at air cleaner housing.
(3) YJ Models: Release the three over-center type
clamps securing the housing to the housing bracket.
XJ Models: Remove the housing cover and remove air
cleaner element. Remove two bolts and one nut.
(4) Release the air cleaner housing from the ambi-
ent air inlet and remove housing from vehicle.
INSTALLATION
(1) Position air cleaner housing to body and ambi-
ent air inlet.
(2) YJ Models: Lock the three over-center type
clamps securing the housing to the housing bracket.
XJ Models: Install two bolts and one nut to housing.
Install air cleaner element and cover.
(3) Install vacuum lines to housing.
Fig. 1 PDCÐYJ Models
Fig. 2 PDCÐXJ Models
14 - 58 FUEL SYSTEM COMPONENT REMOVAL/INSTALLATIONJ
FUEL RAIL ASSEMBLY
REMOVAL
WARNING: THE FUEL SYSTEM IS UNDER CON-
STANT FUEL PRESSURE (EVEN WITH THE ENGINE
OFF) OF APPROXIMATELY 131-269 KPA (19-39 PSI).
THIS PRESSURE MUST BE RELEASED BEFORE
SERVICING THE FUEL RAIL.
(1) Remove fuel tank filler tube cap.
(2) Disconnect the negative battery cable from bat-
tery.
(3) Perform the Fuel System Pressure Release Pro-
cedure as described in the Fuel Delivery System sec-
tion of this Group.
(4) Remove and numerically attach a tag (if fuel
injector is not already tagged), the injector harness
connectors. Do this at each injector (Fig. 12).
(5) Disconnect vacuum line from fuel pressure reg-
ulator (Fig. 12).
(6) Disconnect fuel supply line from fuel rail and
the fuel return line from fuel pressure regulator (Fig.
12). Refer to Fuel Tubes/Lines/Hoses and Clamps, or
Quick-Connect Fittings. These can both be found in
the Fuel Delivery section of this group.
(7) Remove fuel rail mounting bolts.
On models with automatic transmissions, it may be
necessary to remove automatic transmission throttle
line pressure cable and bracket. This will aid in fuel
rail assembly removal.
(8) Remove fuel rail by gently rocking until all the
fuel injectors are out of the intake manifold.
INSTALLATION
(1) Position tips of all fuel injectors into the corre-
sponding injector bore in the intake manifold. Seat
injectors into manifold.
(2) Tighten fuel rail mounting bolts to 27 Nzm (20
ft. lbs.) torque.
(3) Connect injector harness connectors to appro-
priate (tagged) injector.
(4) Connect both fuel lines to fuel rail. Refer to the
Fuel Delivery section of this group for procedures.
(5) Connect vacuum supply line to fuel pressure
regulator.
(6) Install protective cap to pressure test port fit-
ting.
(7) Install fuel tank cap.
(8) Connect negative battery cable to battery.
(9) Start engine and check for fuel leaks.
FUEL SYSTEM PRESSURE RELEASE PROCEDURE
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE (EVEN WITH THE ENGINE OFF)
OF APPROXIMATELY 100 KPA (14.5 PSI). BEFORE
SERVICING THE FUEL PUMP, FUEL RAIL, FUELLINES, FUEL FILTER OR FUEL INJECTOR, THE
FUEL SYSTEM PRESSURE MUST BE RELEASED.
Refer to the Fuel Delivery System section of this
group. See Fuel Pressure Release procedure.
FUEL TANKS
Refer to the Fuel Tank section of this group for re-
moval/installation procedures.
FUEL TANK PRESSURE RELIEF/ROLLOVER VALVE
Refer to the Fuel Tank section of this group for re-
moval/installation procedures.
FUEL TUBES/LINES/HOSES AND CLAMPS
Refer to the Fuel Delivery System section of this
group for removal/installation procedures. Also refer
to Quick-Connect Fittings in the Fuel Delivery sec-
tion of this group.
IDLE AIR CONTROL (IAC) MOTOR
The IAC motor is mounted to the throttle body ad-
jacent to the throttle position sensor (Fig. 14).
REMOVAL
(1) Disconnect the electrical connector from the
IAC motor.
(2) Remove IAC motor torx head mounting bolts.
(3) Remove IAC motor.
INSTALLATION
(1) Install IAC motor into throttle body and
tighten retaining bolts.
(2) Connect electrical connector to IAC motor.
IGNITION COIL
Refer to Group 8D, Ignition Systems for removal/
installation procedures.
Fig. 14 Idle Air Control MotorÐRemoval/
InstallationÐTypical
14 - 62 FUEL SYSTEM COMPONENT REMOVAL/INSTALLATIONJ
(2) Place a small container or shop towel beneath
the switch to collect any excess fluid.
(3) Remove the switch.
INSTALLATION
(1) Install the power steering switch.
(2) Connect the electrical connector to the switch.
(3) Check power steering fluid and add as neces-
sary.
(4) Start the engine and again check power steer-
ing fluid. Add fluid if necessary.
POWERTRAIN CONTROL MODULE (PCM)
On XJ models, the PCM is located in the engine
compartment next to the air cleaner (Fig. 19). On YJ
models, the PCM is located in the engine compart-
ment behind the windshield washer fluid reservoir
(Fig. 20).
REMOVAL
(1) Disconnect the negative battery cable at the
battery.(2) YJ Models Only: Remove the windshield
washer fluid tank.
(3) Loosen the 60-Way connector mounting bolt
(Figs. 19 or 20).
(4) Remove the electrical connector by pulling
straight back.
(5) Remove the three PCM mounting bolts.
(6) Remove PCM.
INSTALLATION
(1) After the PCM electrical connector has been
separated from the PCM, inspect the pins for corro-
sion, being spread apart, bent or misaligned. Also in-
spect the pin heights in the connector. If the pin
heights are different, this would indicate a pin has
separated from the connector. Repair as necessary.
(2) Install PCM. Tighten three mounting bolts to 1
Nzm (9 in. lbs.) torque.
(3) Engage 60-way connector into PCM. Tighten
connector mounting bolt to 4 Nzm (35 in. lbs.) torque.
(4) YJ Models: Install windshield washer fluid
tank.
(5) Connect negative cable to battery.
QUICK-CONNECT FITTINGS
Refer to the Fuel Delivery System section of this
group for removal/installation procedures.
THROTTLE BODY
REMOVAL
(1) Disconnect the negative battery cable.
(2) Disconnect air cleaner hose from throttle body.
(3) Disconnect idle air control motor and throttle
position sensor wire connectors.
(4) Disconnect accelerator cable, throttle cable (au-
tomatic transmission) and speed control cable (if
equipped) from throttle arm (Fig. 21).
(5) Remove throttle body mounting bolts (Fig. 22),
throttle body and gasket. Discard old gasket.
Fig. 18 Power Steering Pressure SwitchÐXJ Models
Fig. 19 PCM LocationÐXJ Models
Fig. 20 PCM LocationÐYJ Models
14 - 64 FUEL SYSTEM COMPONENT REMOVAL/INSTALLATIONJ
The stop lamp and turn signal plug-in relays are
located behind left quarter trim panel (Fig. 3).
HITCH REMOVALÐXJ VEHICLES
An XJ class III, weight-distributing/equalizer type
hitch (Fig. 4)is comprised of:
²Towing tube with a ball mount receptacle.
²Various reinforcement/support brackets that are
attached to the vehicle frame sills and rear cross-
member with bolts.(1) If necessary, remove the trailer tow wire har-
ness connector from the hitch (Fig. 5).
(2) Support the hitch.
(3) Remove the bolts that attach the towing tube to
the frame sills and reinforcement bracket. If
equipped, remove the fuel tank skid plate.
The reinforcement brackets are held on the
frame sills with two blind rivets.
(4) Remove the bolts from the plate bracket and
rear crossmember and lower the support and hitch.
Fig. 4 Equalizer Type HitchÐXJ Vehicles
Fig. 2 Class III Trailer Tow Wire Harness and
ConnectorsFig. 3 Class III Trailer Tow Wire Harness Plug-In
Relays
23 - 78 TRAILER HITCHJ
PRESSURE RELIEF/ROLLOVER VALVE
All vehicles are equipped with a combination fuel
tank pressure relief and rollover valve (Fig. 10). This
dual function valve will relieve fuel tank pressure
and also prevent fuel flow through the fuel tank vent
hoses in the event of an accidental vehicle rollover.The valve incorporates a pressure relief mechanism
(Fig. 11) that releases fuel tank pressure when the
pressure increases above the calibrated sealing value.
Refer to the Fuel Tank section of Group 14, Fuel Sys-
tems for removal and installation procedures.
OXYGEN (O2S) SENSOR
For description, operation, diagnosis and removal/
installation procedures of the O2S sensor, refer to
Group 14, Fuel Systems.
Fig. 10 Pressure Relief/Rollover Valve LocationÐ
Typical
Fig. 11 Typical Pressure Relief/Rollover Valve
Operation
25 - 6 EMISSION CONTROL SYSTEMSJ
COMPONENT REMOVAL/INSTALLATION
INDEX
page page
Air Cleaner Element........................ 7
Coolant Temperature Sensor.................. 7
EVAP Canister............................ 7
Fuel Tank Filler Tube Cap.................... 7Oxygen (O2S) Sensor....................... 7
Powertrain Control Module (PCM).............. 7
Pressure Relief/Rollover Valve................. 7
AIR CLEANER ELEMENT
For removal and installation procedures of both the
air cleaner housing and the air cleaner element, refer
to the Group 14, Fuel System.
COOLANT TEMPERATURE SENSOR
For description, operation, diagnosis and removal/
installation procedures of the engine coolant temper-
ature sensor, refer to Group 14, Fuel Systems.
EVAP CANISTER
On XJ models, the EVAP canister is located in the
engine compartment on the passenger side frame rail
(Fig. 1). On YJ models, the EVAP canister is located
in the engine compartment on the dash panel and be-
low the brake master cylinder (Fig. 2).
REMOVAL/INSTALLATION
(1) Disconnect the vacuum lines at the EVAP can-
ister. Note location of lines before removal.(2) Remove canister retaining strap bolt.
(3) Remove canister from vehicle.
Reverse the procedure for installation.
FUEL TANK FILLER TUBE CAP
If replacement of the fuel filler tube cap (fuel tank
cap) is necessary, it must be replaced with aniden-
tical capto be sure of correct system operation.
OXYGEN (O2S) SENSOR
For description, operation, diagnosis and removal/
installation procedures of the O2S sensor, refer to
Group 14, Fuel Systems.
POWERTRAIN CONTROL MODULE (PCM)
For removal and installation procedures, refer to
Group 14, Fuel Systems.
PRESSURE RELIEF/ROLLOVER VALVE
For removal and installation procedures, refer to
the Fuel Tank section of Group 14, Fuel Systems.
Fig. 1 EVAP CanisterÐXJ Models
Fig. 2 EVAP CanisterÐYJ Models
JEMISSION CONTROL SYSTEMS 25 - 7