Engine coolant sensor JEEP GRAND CHEROKEE 2002 WJ / 2.G Owner's Guide

ENGINE CONTROL MODULE C2 (DIESEL) - BLACK 40 WAY
CAV CIRCUIT FUNCTION
105 - -
106 - -
107 - -
108 - -
109 - -
110 - -
111 - -
112 T41 20BK/WT PARK/NEUTRAL POSITION SWITCH SENSE (T41)
113 - -
114 - -
115 K14 14BK/YL FUEL INJECTOR NO. 4 CONTROL
116 K63 14BK COMMON INJECTOR DRIVER
117 - -
118 K11 14BK/DB FUEL INJECTOR NO. 1 CONTROL
119 K38 14BK/DG FUEL INJECTOR NO. 5 CONTROL
120 K12 14BK/VT FUEL INJECTOR NO. 2 CONTROL
121 K13 14BK/RD FUEL INJECTOR NO. 3 CONTROL
ENGINE COOLANT TEMPERATURE SENSOR (DIESEL) - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 K4 20BK/LB SENSOR GROUND
2 K2 20DG/RD ENGINE COOLANT TEMPERATURE SENSOR SIGNAL
ENGINE COOLANT TEMPERATURE SENSOR (GAS) - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 K4 18BK/LB SENSOR GROUND
2 K2 18TN/BK ENGINE COOLANT TEMPERATURE SENSOR SIGNAL
ENGINE OIL PRESSURE SENSOR (DIESEL) - BLACK 3 WAY
CAV CIRCUIT FUNCTION
1 K6 18VT/WT SENSOR REFERENCE VOLTAGE B
2 G60 20BR/DB ENGINE OIL PRESSURE SENSOR SIGNAL
3 K4 18BK/LB SENSOR GROUND
WJ8W-80 CONNECTOR PIN-OUT 8W - 80 - 77

POWER CONNECTOR - WHITE 2 WAY
CAV CIRCUIT FUNCTION
1 F85 16VT/WT FUSED B(+)
2 Z234 16BK GROUND
POWERTRAIN CONTROL MODULE C1 (GAS) - BLACK 32 WAY
CAV CIRCUIT FUNCTION
1 K93 14TN/OR COIL DRIVER NO. 3
2 F991 18OR/DB FUSED IGNITION SWITCH OUTPUT (RUN-START)
3 K94 14TN/LG (4.7L) COIL DRIVER NO. 4
4 K4 18BK/LB SENSOR GROUND
5 K96 14TN/LB (4.7L) COIL DRIVER NO. 6
6 T41 18BK/WT PARK/NEUTRAL POSITION SWITCH SENSE (T41)
7 K91 14TN/RD COIL DRIVER NO. 1
8 K24 18GY/BK CRANKSHAFT POSITION SENSOR SIGNAL
9 K98 14LB/RD (4.7L) COIL DRIVER NO. 8
10 K60 18YL/BK IDLE AIR CONTROL NO. 2 DRIVER
11 K40 18BR/WT IDLE AIR CONTROL NO. 3 DRIVER
12 - -
13 - -
14 K77 18LG/BK TRANSFER CASE POSITION SENSOR INPUT
15 K21 18BK/RD INTAKE AIR TEMPERATURE SENSOR SIGNAL
16 K2 18TN/BK ENGINE COOLANT TEMPERATURE SENSOR SIGNAL
17 K7 18OR 5 VOLT SUPPLY
18 K44 18TN/YL CAMSHAFT POSITION SENSOR SIGNAL
19 K39 18GY/BK IDLE AIR CONTROL NO. 1 DRIVER
20 K59 18VT/BK IDLE AIR CONTROL NO. 4 DRIVER
21 K95 14TN/DG (4.7L) COIL DRIVER NO. 5
22 A7 14RD/BK FUSED B(+)
23 K22 18OR/RD THROTTLE POSITION SENSOR SIGNAL
24 K41 18BK/DG OXYGEN SENSOR 1/1 SIGNAL
25 K141 18TN/WT OXYGEN SENSOR 1/2 SIGNAL
26 K241 18LG/RD (EXCEPT 4.0L
BUILT-UP-EXPORT)OXYGEN SENSOR 2/1 SIGNAL
27 K1 18DG/RD MAP SENSOR SIGNAL
28 - -
29 K341 18TN/WT (4.0L EXCEPT
BUILT-UP-EXPORT)OXYGEN SENSOR 2/2 SIGNAL
29 K341 18PK/WT (4.7L) OXYGEN SENSOR 2/2 SIGNAL
30 - -
31 Z82 14BK/WT GROUND
32 Z81 14BK/TN GROUND
8W - 80 - 108 8W-80 CONNECTOR PIN-OUTWJ

CONNECTOR NAME/
NUMBERCOLOR LOCATION FIG.
Coil On Plug NO. 8 (4.7L) BK Right Side of Engine Near Fuel
Injector No.814, 15
Coil Rail (4.0L) BK Right Rear of Engine 10, 11
Compact Disc Changer BK Near Radio N/S
Compact Disc Changer BK Right Rear Quarter Panel 37
Controller Antilock Brake BK Left Front Engine Compartment 3, 4
Coolant Level Sensor LT GY Right Rear of Engine 5
Crankcase Heater (Diesel) BK Near T/O for G105 8
Crankshaft Position Sensor
(Diesel)BK Rear of Engine Near Transmission
Bell HousingN/S
Crankshaft Position Sensor
(Gas)BK Rear of Engine Near Transmission
Bell Housing10, 11, 14, 15, 17
Data Link Connector BK Under Lower Driver's Side of
Instrument Panel20, 21, 22
Diagnostic Junction Port BK At Steering Column 23
Driver Airbag Squib 1 BK In Steering Wheel N/S
Driver Airbag Squib 2 BK In Steering Wheel N/S
Driver Blend Door Motor/
Actuator (AZC)BK On HVAC Housing N/S
Driver Cylinder Lock Switch GY In Driver Door 24, 25
Driver Door Lock Motor/Ajar
SwitchBK In Driver Door 24, 25
Driver Door Module - C1 WT In Driver Door 24, 25
Driver Door Module - C2 BK In Driver Door N/S
Driver Door Module - C3 BK In Driver Door N/S
Driver Front Door Courtesy
LampBK In Driver Door N/S
Driver Front Power Window
MotorBK In Driver Door 24, 25
Driver Heated Seat Back
(Premium I/III)GN At Driver Seat N/S
Driver Heated Seat Cushion
(Premium I/III)BK At Driver Seat N/S
Driver Heated Seat Switch WT Center of Instrument Panel 19 20, 21
Driver Lumbar Motor
(Midline/Premium)BK At Driver Seat N/S
Driver Lumbar Switch
(Midline/Premium)WT At Driver Seat N/S
Driver Power Mirror BK At Driver Door N/S
Driver Power Seat Front Riser
MotorRD At Driver Seat N/S
Driver Power Seat Front Riser
Motor Sensor (Premium II/III)BK At Driver Seat N/S
Driver Power Seat Horizontal
MotorBK At Driver Seat N/S
8W - 91 - 4 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONWJ
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/
NUMBERCOLOR LOCATION FIG.
Driver Power Seat Horizontal
Motor Sensor (Premium II/III)BK At Driver Seat N/S
Driver Power Seat Rear Riser
MotorRD At Driver Seat N/S
Driver Power Seat Rear Riser
Motor Sensor (Premium II/III)BK At Driver Seat N/S
Driver Power Seat Recliner
MotorBK At Driver Seat N/S
Driver Power Seat Recliner
Motor Sensor (Premium II/III)BK At Driver Seat N/S
Driver Power Seat Switch
(Midline/Premium)GN At Driver Seat N/S
Driver Rear Power Window
MotorBK In Left Rear Door 28
Driver Rear Power Window
SwitchBL In Left Rear Door 28
Driver Seat Belt Switch At Switch N/S
EGR Solenoid (Diesel) BK Left Front Fender 7, 8
Electric Brake BL Near Junction Block N/S
Electronic Speed Control Servo BK Right Front of Engine Compartment 5
Engine Control Module C1
(Diesel)BK Left Front of Engine 7, 8
Engine Control Module C2
(Diesel)BK Left Front of Engine 7, 8
Engine Coolant Temperature
Sensor (Diesel)BK Top of Engine N/S
Engine Coolant Temperature
Sensor (GAS)BK Front of Engine 9, 13
Engine Oil Pressure Sensor BK Side of Engine 10, 11, 13
EVAP/Purge Solenoid BK Left Front Fender Near Controller
Antilock Brake3
Front Power Outlet RD Center of Instrument Panel 19, 20
Front Washer Pump WT Left Front of Engine Compartment 3, 4
Front Wiper Motor BK Left Side of Cowl 3, 4
Fuel Injector No.1 BK At Injector 7, 9, 13
Fuel Injector No.2 BK At Injector 7, 9, 14, 15
Fuel Injector No.3 BK At Injector 7, 9, 13
Fuel Injector No.4 BK At Injector 7, 9, 14, 15
Fuel Injector No.5 BK At Injector 9, 13
Fuel Injector No.6 BK At Injector 9, 14, 15
Fuel Injector No.7 (4.7L) BK At Injector 13
Fuel Injector No.8 (4.7L) BK At Injector 14, 15
Fuel Pressure Sensor (Diesel) BK Right Front of Engine N/S
Fuel Pressure Solenoid
(Diesel)BK Top of Engine N/S
WJ8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 5
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

SPLICE
NUMBERLOCATION FIG.
S122 (4.0L) Near T/O for G103 10, 11
S122 (4.7L) LHD Near T/O for Input Speed Sensor 15
S122 (4.7L) RHD Near T/O for Powertrain Control Module 16
S122 (Diesel) Near T/O for Generator N/S
S123 (4.0L) Near T/O for Capacitor 10, 11
S124 (4.7L) In Trough Near T/O for Capacitor No.2 13
S125 (Diesel) In T/O for C103 and C105 Left Rear of Engine Compartment N/S
S125 (Gas) Near T/O for Powertrain Control Module - C3 N/S
S126 (4.0L) LHD Near T/O for Battery Temperature Sensor N/S
S126 (4.0L) RHD In Trough Near T/O for Powertrain Control Module - C3 N/S
S127 (LHD) Gas In Trough Near T/O for Powertrain Control Module - C3 N/S
S127 (RHD) Gas In T/O for Power Distribution Center 5
S127 (Diesel) Near T/O for Power Distribution Center 4
S128 (Diesel) In T/O for C102 Left Rear of Engine Compartment N/S
S128 (LHD) Gas In Trough Near T/O for Powertrain Control Module - C3 N/S
S128 (RHD) Gas In T/O for C102 5
S130 (LHD) Gas In T/O for C102 N/S
S130 (RHD) Gas In T/O for Controller Antilock Brake 3
S130 (Diesel) In T/O for Controller Anti-Lock Brake 4
S131 In Trough Near T/O for Power Distribution Center 5
S131 (Diesel) Near T/O for Power Distribution Center 4
S132 (Diesel) Near T/O for EGR Solenoid N/S
S132 (Gas) Near T/O for Battery Temperature Sensor 5
S133 (Diesel) In Trough Near T/O for EGR Solenoid N/S
S133 (Gas) Near T/O for Battery Temperature Sensor 5
S134 (Diesel) In Trough Near T/O for G106/G107 4
S134 (Gas) In Trough Near T/O for Controller Anti-Lock Brake 3
S135 (Diesel) Near T/O for Engine Control Module C1 7, 8
S136 (Diesel) Near T/O for Engine Control Module C1 7, 8
S137 (Diesel) In Trough Near T/O for Coolant Level Sensor N/S
S139 (Diesel) Near T/O for Engine Control Module C1 7, 8
S140 (Diesel) Near T/O for Power Distribution Center 4
S140 (Gas) Near T/O for Controller Antilock Brake N/S
S141 (Gas) Near T/O for Controller Antilock Brake 3
S142 (Diesel) In Trough Near T/O for Coolant Level Sensor N/S
S142 Gas In T/O for C102 5
S143 (Diesel) In Trough Near T/O for Hood Ajar Switch 4
S143 (Gas,
Built-Up-Export)
LHDIn Trough Near T/O for Controller Antilock Brake 3
S143 Gas RHD Near T/O for Evap/Purge Solenoid N/S
S145 (Diesel) Near T/O for Engine Control Module C1 7, 8
WJ8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 13
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

(7) Remove the fan assembly from the water pump
(Refer to 7 - COOLING/ENGINE/RADIATOR FAN -
REMOVAL).
(8) Remove the fan shroud.
(9) Disconnect the transmission fluid cooler lines
(automatic transmission).
(10) Discharge the A/C system (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).
(11) Remove the service valves and cap the com-
pressor ports.
(12) Remove the radiator or radiator/condenser (if
equipped with A/C).
(13) Disconnect the heater hoses at the engine
thermostat housing and water pump.
(14) Disconnect the accelerator cable, transmission
line pressure cable and speed control cable (if
equipped) from the throttle body.
(15) Remove cables from the bracket and secure
out of the way.
(16) Disconnect the body ground at the engine.
(17) Disconnect the following connectors and
secure their harness out of the way.
²Power steering pressure switch
²Coolant temperature sensor
²Six (6) fuel injector connectors
²Intake air temperature sensor
²Throttle position sensor
²Map sensor
²Crankshaft position sensor
²Oxygen sensor
²Camshaft position sensor
²Generator connector and B+ terminal wire
(18) Disconnect the coil rail electrical connections
and the oil pressure switch connector.
(19) Perform the fuel pressure release procedure
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).
(20) Disconnect the fuel supply line at the injector
rail (Refer to 14 - FUEL SYSTEM/FUEL DELIVERY/
QUICK CONNECT FITTING - STANDARD PROCE-
DURE).
(21) Remove the fuel line bracket from the intake
manifold.
(22) Remove the air cleaner assembly (Fig. 5).
(23) Disconnect the hoses from the fittings at the
steering gear.
(24) Drain the pump reservoir.
(25) Cap the fittings on the hoses and steering
gear to prevent foreign objects from entering the sys-
tem.
(26) Raise and support the vehicle.
(27) Disconnect the wires from the engine starter
motor solenoid.(28) Remove the engine starter motor (Refer to 8 -
ELECTRICAL/STARTING/STARTER MOTOR -
REMOVAL).
(29) Disconnect the oxygen sensor from the
exhaust pipe.
(30) Disconnect the exhaust pipe from the mani-
fold.
(31) Remove the exhaust pipe support.
(32) Remove the bending brace (Refer to 9 -
ENGINE/ENGINE BLOCK/STRUCT SUPPORT -
REMOVAL).
(33) Remove the engine flywheel/converter housing
access cover.
(34) Mark the converter and drive plate location.
(35) Remove the converter-to-drive plate bolts.
(36) Remove the upper engine flywheel/converter
housing bolts and loosen the bottom bolts.
(37) Remove the engine mount cushion-to-engine
compartment bracket bolts.
(38) Lower the vehicle.
(39) Attach a lifting device to the engine.
(40) Raise the engine off the front supports.
(41) Place a support or floor jack under the con-
verter (or engine flywheel) housing.
(42) Remove the remaining converter (or engine
flywheel) housing bolts.
(43) Lift the engine out of the engine compart-
ment.
Fig. 5 Air Cleaner Assembly
1 - POWER STEERING PUMP
2 - AIR CLEANER ASSEMBLY
9 - 12 ENGINE - 4.0LWJ
ENGINE - 4.0L (Continued)

INSTALLATION
CAUTION: When installing the engine into a vehicle
equipped with an automatic transmission, be care-
ful not to damage the trigger wheel on the engine
flywheel.
(1) Attach a lifting device to the engine and lower
the engine into the engine compartment. For easier
installation, it may be necessary to remove the
engine mount bracket as an aid in alignment of the
engine to the transmission.
(2) Align the transmission torque converter hous-
ing with the engine.
(3) Loosely install the converter housing lower
bolts and install the next higher bolt and nut on each
side.
(4) Tighten all 4 bolts finger tight.
(5) Install the engine mount brackets (if removed).
(6) Lower the engine and engine mount brackets
onto the engine compartment cushions. Install the
bolts and finger tighten the nuts.
(7) Remove the engine lifting device.
(8) Raise and support the vehicle.
(9) Install the remaining engine flywheel/converter
housing bolts. Tighten all bolts to 38 N´m (28 ft. lbs.)
torque.
(10) Install the converter-to-drive plate bolts.
(11) Ensure the installation reference marks are
aligned.
(12) Install the engine flywheel/converter housing
access cover.
(13) Install the exhaust pipe support and tighten
the screw.
(14) Install the engine bending brace (Refer to 9 -
ENGINE/ENGINE BLOCK/STRUCT SUPPORT -
INSTALLATION).
(15) Tighten the engine mount-to-bracket bolts.
(16) Connect the vehicle speed sensor wire connec-
tions and tighten the screws.
(17) Connect the exhaust pipe to the manifold.
(18) Install the engine starter motor (Refer to 8 -
ELECTRICAL/STARTING/STARTER MOTOR -
INSTALLATION).
(19) Connect the wires to the engine starter motor
solenoid.
(20) Lower the vehicle.
(21) Connect all the vacuum hoses and wire con-
nectors identified during engine removal.
(22) Remove protective caps from the power steer-
ing hoses.
(23) Connect the hoses to the fittings at the steer-
ing gear. Tighten the nut to 52 N´m (38 ft. lbs.)
torque.
(24) Fill the pump reservoir with fluid.(25) Inspect the fuel supply line o-ring(s) and
replace if necessary. Connect fuel supply line to injec-
tior rail and verify connection by pulling outward on
the line.
(26) Install the fuel line bracket to the intake
manifold.
(27) Connect the coil rail electrical connectors and
oil pressure switch connector.
(28) Connect the following electrical connectors:
²Power steering pressure switch
²Coolant temperature sensor
²Six (6) fuel injector connectors
²Intake air temperature sensor
²Throttle position sensor
²Map sensor
²Crankshaft position sensor
²Oxygen sensor
²Camshaft position sensor
²Generator connector and B+ terminal wire
(29) Connect all previously removed vacuum hoses.
(30) Connect the body ground strap.
(31) Install the throttle, transmission line pres-
sure, and speed control cables to their mounting
bracket and connect them to the throttle body.
(32) Connect the heater hoses at the engine ther-
mostat housing and water pump.
(33) Install the fan assembly (Refer to 7 - COOL-
ING/ENGINE/RADIATOR FAN - INSTALLATION).
(34) Place the fan shroud in position over the fan.
(35) Install the radiator (Refer to 7 - COOLING/
ENGINE/RADIATOR - INSTALLATION).
(36) Connect the service valves to the A/C com-
pressor ports, if equipped with A/C.
(37) Charge the air conditioner system (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE).
(38) Connect the radiator hoses and automatic
transmission fluid cooler pipes, if equipped.
(39) Install the fan shroud to the radiator or radi-
ator/condenser (if equipped with A/C).
(40) Install upper radiator support.
(41) Connect the upper radiator hose and tighten
the clamp.
(42) Connect the lower radiator hose and tighten
the clamp.
(43) Fill crankcase with engine oil. (Refer to
LUBRICATION & MAINTENANCE/FLUID CAPACI-
TIES - SPECIFICATIONS) for correct capacities.
(44) Fill the cooling system with reusable coolant
or new coolant (Refer to 7 - COOLING - STANDARD
PROCEDURE).
(45) Align the hood to the scribe marks. Install the
hood.
(46) Install the air cleaner assembly.
(47) Install the battery and connect the battery
cable.
WJENGINE - 4.0L 9 - 13
ENGINE - 4.0L (Continued)

REMOVAL
REMOVAL - CAMSHAFT BEARINGS
The camshaft rotates within four steel-shelled,
babbitt-lined bearings that are pressed into the cyl-
inder block and then line reamed. The camshaft
bearing bores and bearing diameters are not the
same size. They are stepped down in 0.254 mm
(0.010 inch) increments from the front bearing (larg-
est) to the rear bearing (smallest). This permits eas-
ier removal and installation of the camshaft. The
camshaft bearings are pressure lubricated. Camshaft
end play is maintained by the thrust plate.
(1) Remove the camshaft (Refer to 9 - ENGINE/
ENGINE BLOCK/CAMSHAFT & BEARINGS (IN
BLOCK) - REMOVAL).
NOTE: It is not advisable to attempt to replace cam-
shaft bearings unless special removal and installa-
tion tools are available, such as recommended tool
8544 Camshaft Bushing Remover Installer.
(2) Using Special tool 8544 Camshaft Bushing
Remover Installer, remove the camshaft bearings.
REMOVAL - CAMSHAFT
WARNING: THE COOLANT IN A RECENTLY OPER-
ATED ENGINE IS HOT AND PRESSURIZED.RELEASE THE PRESSURE BEFORE REMOVING
THE DRAIN COCK, CAP AND DRAIN PLUGS.
(1) Disconnect negative cable from battery.
(2) Drain the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(3) Remove the radiator (Refer to 7 - COOLING/
ENGINE/RADIATOR - REMOVAL) and condenser
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING/A/C CONDENSER - REMOVAL), if
equipped with A/C.
(4) Remove the engine cylinder head cover (Refer
to 9 - ENGINE/CYLINDER HEAD/CYLINDER
HEAD COVER(S) - REMOVAL).
(5) Remove the rocker arms, bridges and pivots
(Refer to 9 - ENGINE/CYLINDER HEAD/ROCKER
ARM / ADJUSTER ASSY - REMOVAL).
(6) Remove the push rods.
(7) Remove the engine cylinder head and gasket
(Refer to 9 - ENGINE/CYLINDER HEAD - REMOV-
AL).
(8) Remove the hydraulic valve tappets from the
engine cylinder block (Refer to 9 - ENGINE/ENGINE
BLOCK/HYDRAULIC LIFTERS (CAM IN BLOCK) -
REMOVAL).
(9) Remove the vibration damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL).
(10) Remove the timing case cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL).
(11) Rotate the crankshaft until the crankshaft
sprocket timing mark is aligned on centerline with
the camshaft sprocket timing mark (Fig. 32).
(12) Remove the timing chain and sprockets (Refer
to 9 - ENGINE/VALVE TIMING/TIMING BELT/
CHAIN AND SPROCKETS - REMOVAL).
(13) Remove the front bumper and/or grille, as
required.
(14) Remove the two thrust plate retaining screws,
thrust plate and camshaft (Fig. 31).
INSPECTION
INSPECTION - CAMSHAFT BEARINGS
(1) Inspect the bearing journals for uneven wear
pattern or finish.
(2) Inspect the bearings for wear.
INSPECTION - CAMSHAFT
(1) Inspect the cam lobes for wear.
(2) Inspect the camshaft position sensor drive gear
for wear.
(3) If the camshaft appears to have been rubbing
against the thrust washer, examine the oil pressure
Fig. 30 CamshaftÐTypical
1 - CAMSHAFT
2 - LOBES
3 - BEARING JOURNAL
WJENGINE - 4.0L 9 - 31
CAMSHAFT & BEARINGS (Continued)

INSTALLATION
A gear-type oil pump is mounted at the underside
of the cylinder block opposite the No.4 main bearing.
(1) Install the oil pump on the cylinder block using
a replacement gasket. Tighten the bolts to 23 N´m
(17 ft. lbs.) torque.
(2) Install the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION).
(3) Fill the oil pan with oil to the specified level.
INTAKE MANIFOLD
DESCRIPTION
The intake manifold (Fig. 83) is made of cast alu-
minum and uses eleven bolts to mount to the cylin-
der head. This mounting style improves sealing and
reduces the chance of leaks.
DIAGNOSIS AND TESTING - INTAKE
MANIFOLD LEAKAGE
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
(2) Spray a small stream of water at the suspected
leak area.
(3) If a change in RPM is observed the area of the
suspected leak has been found.
(4) Repair as required.
REMOVAL
NOTE: THE ENGINE INTAKE AND EXHAUST MANI-
FOLD MUST BE REMOVED AND INSTALLED
TOGETHER. THE MANIFOLDS USE A COMMON
GASKET AT THE CYLINDER HEAD.
(1) Disconnect the battery negative cable.
(2) Remove air cleaner inlet hose from the resona-
tor assembly.
(3) Remove the air cleaner assembly.
(4) Remove the throttle cable, vehicle speed control
cable (if equipped) and the transmission line pres-
sure cable (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - AW4/THROTTLE VALVE
CABLE - REMOVAL).
(5) Disconnect the following electrical connections
and secure their harness out of the way:
²Throttle Position Sensor
²Idle Air Control Motor
²Coolant Temperature Sensor (at thermostat
housing)
²Intake Air Temperature Sensor
²Oxygen Sensor
²Crank Position Sensor
²Six (6) Fuel Injector Connectors
²Manifold Absolute Pressure (MAP) Sensor.
(6) Disconnect HVAC, and Brake Booster vacuum
supply hoses at the intake manifold.
(7) Perform the fuel pressure release procedure.
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
STANDARD PROCEDURE).
(8) Disconnect and remove the fuel system supply
line from the fuel rail assembly.
(9) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(10) Remove the power steering pump from the
intake manifold and set aside.
(11) Raise the vehicle.
(12) Disconnect the exhaust pipes from the engine
exhaust manifolds.
(13) Lower the vehicle.
(14) Remove the intake manifold and exhaust
manifold bolts and manifolds (Fig. 84).
INSTALLATION
If the manifold is being replaced, ensure all the fit-
ting, etc. are transferred to the replacement mani-
fold.
(1) Install a new engine exhaust/intake manifold
gasket over the alignment dowels on the cylinder
head.
(2) Position the engine exhaust manifolds to the
cylinder head. Install fastener Number 3 and finger
tighten at this time (Fig. 84).
Fig. 83 Intake Manifold 4.0L Engine
WJENGINE - 4.0L 9 - 57
OIL PUMP (Continued)

(13) Disconnect the engine block heater power
cable from the block heater.
(14) Lower vehicle.
(15) Remove throttle body resonator assembly and
inlet hose.
(16) Disconnect throttle and speed control cables.
(17) Disconnect tube from both the left and right
side crankcase breathers, then remove the breathers
(Fig. 5).
(18) Discharge A/C system (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE).(19) Remove radiator fan (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - REMOVAL) and acces-
sory drive belt (Refer to 7 - COOLING/ACCESSORY
DRIVE/DRIVE BELTS - REMOVAL).
(20) Remove A/C compressor (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/A/C COM-
PRESSOR - REMOVAL).
(21) Disconnect transmission oil cooler lines at the
radiator.
(22) Disconnect radiator lower hose at the thermo-
stat housing.
(23) Remove A/C condenser (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/A/C CON-
DENSER - REMOVAL).
(24) Remove radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - REMOVAL).
(25) Remove generator (Refer to 8 - ELECTRICAL/
CHARGING/GENERATOR - REMOVAL).
(26) Disconnect the two heater hoses from the tim-
ing chain cover.
(27) Disconnect engine harness at the following
points :
²Intake air temperature (IAT) sensor (Fig. 6)
²Fuel Injectors
²Throttle Position (TPS) Switch
²Idle Air Control (IAC) Motor
²Engine Oil Pressure Switch
²Engine Coolant Temperature (ECT) Sensor
²Manifold absolute pressure (MAP) Sensor
²Camshaft Position (CMP) Sensor
²Coil Over Plugs
(28) Release fuel rail pressure (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY - STANDARD PROCE-
DURE) then disconnect the fuel supply quick connect
fitting at the fuel rail (Refer to 14 - FUEL SYSTEM/
FUEL DELIVERY/QUICK CONNECT FITTING -
STANDARD PROCEDURE).
(29) Remove power steering pump and position out
of the way.
(30) Disconnect ground straps from the left side of
the engine.
(31) Install Engine Lifting Fixture Special Tool
8347 (Fig. 7)following these steps.
²Holding the lifting fixture at a slight angle, slide
the large bore in the front plate over the hex portion
of the lifting stud.
²Position the two remaining fixture arms onto
the two lifting studs in the cylinder heads.
²Pull foward and upward on the lifting fixture so
that the lifting stud rest in the slotted area below the
large bore.
²Secure the lifting fixture to the three studs
using three 7/16 ± 14 N/C locknuts.
²Make sure the lifting loop in the lifting fixture is
in the last hole (closest to the throttle body) to min-
imize the angle of engine during removal.
Fig. 4 Crankshaft Position Sensor
1 - CRANKSHAFT POSITION SENSOR
2 - CYLINDER HEAD COVER
3 - CAMSHAFT POSITION SENSOR
4 - RIGHT SIDE CYLINDER BLOCK
Fig. 5 Crankcase Breather Connection Points
1 - CRANKCASE BREATHERS
9 - 72 ENGINE - 4.7LWJ
ENGINE - 4.7L (Continued)