Fuel pump JEEP LIBERTY 2002 KJ / 1.G Owner's Manual

Component Page
C316 (Built-Up-Export).............. 8Wa-80-46
C316 (Built-Up-Export).............. 8Wa-80-46
C317 (Except Built-Up-Export)........ 8Wa-80-47
C317 (Except Built-Up-Export)........ 8Wa-80-47
Cabin Heater (Diesel)............... 8Wa-80-47
Camshaft Position Sensor (2.4L)....... 8Wa-80-47
Camshaft Position Sensor (3.7L)....... 8Wa-80-47
Camshaft Position Sensor (Diesel)...... 8Wa-80-48
Capacitor......................... 8Wa-80-48
Cargo Lamp (Except Base)........... 8Wa-80-48
CD Changer...................... 8Wa-80-48
Center High Mounted Stop Lamp...... 8Wa-80-49
Cigar Lighter..................... 8Wa-80-49
Clockspring C1.................... 8Wa-80-49
Clockspring C2.................... 8Wa-80-49
Clockspring C3.................... 8Wa-80-49
Clutch Interlock Switch (M/T)......... 8Wa-80-50
Coil On Plug No. 1 (3.7L)............ 8Wa-80-50
Coil On Plug No. 2 (3.7L)............ 8Wa-80-50
Coil On Plug No. 3 (3.7L)............ 8Wa-80-50
Coil On Plug No. 4 (3.7L)............ 8Wa-80-50
Coil On Plug No. 5 (3.7L)............ 8Wa-80-51
Coil On Plug No. 6 (3.7L)............ 8Wa-80-51
Coil Rail (2.4L).................... 8Wa-80-51
Compass Mini-Trip Computer
(Premium)...................... 8Wa-80-51
Controller Antilock Brake............ 8Wa-80-52
Crankshaft Position Sensor (2.4L)...... 8Wa-80-52
Crankshaft Position Sensor (3.7L)...... 8Wa-80-52
Crankshaft Position Sensor (Diesel).... 8Wa-80-53
Data Link Connector................ 8Wa-80-53
Diagnostic Junction Port............. 8Wa-80-53
Dome Lamp (Base)................. 8Wa-80-54
Driver Airbag Squib 1............... 8Wa-80-54
Driver Airbag Squib 2............... 8Wa-80-54
Driver Seat Belt Switch............. 8Wa-80-54
Driver Seat Belt Tensioner........... 8Wa-80-54
EGR Solenoid (Diesel)............... 8Wa-80-55
Engine Control Module C1........... 8Wa-80-55
Engine Control Module C2........... 8Wa-80-56
Engine Coolant Level Sensor (Diesel) . . . 8Wa-80-57
Engine Coolant Temp Sensor (Diesel) . . . 8Wa-80-57
Engine Coolant Temperature
Sensor (Gas).................... 8Wa-80-58
Engine Oil Pressure Sensor........... 8Wa-80-58
Evap/Purge Solenoid................ 8Wa-80-58
Flip-Up Glass Release Motor.......... 8Wa-80-58
Flip-Up Glass Release Switch......... 8Wa-80-58
Front Wiper Motor................. 8Wa-80-59
Fuel Heater (Diesel)................ 8Wa-80-59
Fuel Injector No. 1 (Diesel)........... 8Wa-80-59
Fuel Injector No. 1 (Gas)............. 8Wa-80-59
Fuel Injector No. 2 (Diesel)........... 8Wa-80-59
Fuel Injector No. 2 (Gas)............. 8Wa-80-60Component Page
Fuel Injector No. 3 (Diesel)........... 8Wa-80-60
Fuel Injector No. 3 (Gas)............. 8Wa-80-60
Fuel Injector No. 4 (Diesel)........... 8Wa-80-60
Fuel Injector No. 4 (Gas)............. 8Wa-80-60
Fuel Injector No. 5 (3.7L)............ 8Wa-80-61
Fuel Injector No. 6 (3.7L)............ 8Wa-80-61
Fuel Pressure Sensor (Diesel)......... 8Wa-80-61
Fuel Pressure Solenoid (Diesel)........ 8Wa-80-61
Fuel Pump Module................. 8Wa-80-61
G202............................ 8Wa-80-61
Generator........................ 8Wa-80-62
Glow Plug Assembly (Diesel).......... 8Wa-80-62
Hazard Switch/Combination Flasher.... 8Wa-80-62
Headlamp Leveling Switch
(Built-Up-Export)................ 8Wa-80-63
Heated Seat Module (Highline)........ 8Wa-80-63
High Note Horn.................... 8Wa-80-63
Hood Ajar Switch (Except Base)....... 8Wa-80-63
Idle Air Control Motor............... 8Wa-80-64
Ignition Switch.................... 8Wa-80-64
Input Speed Sensor (3.7L)............ 8Wa-80-64
Instrument Cluster................. 8Wa-80-64
Intake Air Temperature Sensor (Gas) . . . 8Wa-80-65
Intrusion Sensor (Built-Up-Export)..... 8Wa-80-65
Junction Block Body Control Module-JB . 8Wa-80-65
Junction Block C1.................. 8Wa-80-66
Junction Block C2.................. 8Wa-80-67
Junction Block C3.................. 8Wa-80-68
Knock Sensor (3.7L)................ 8Wa-80-69
Leak Detection Pump............... 8Wa-80-69
Left Courtesy Lamp................ 8Wa-80-69
Left Curtain Airbag................. 8Wa-80-69
Left Cylinder Lock Switch (Except Base) . 8Wa-80-69
Left Door Lock Switch (Except Base) . . . 8Wa-80-70
Left Fog Lamp..................... 8Wa-80-70
Left Front Door Ajar Switch (Base)..... 8Wa-80-70
Left Front Door Lock Motor/Ajar Switch
(Except Base)................... 8Wa-80-70
Left Front Door Speaker (Base)........ 8Wa-80-70
Left Front Door Speaker (Premium).... 8Wa-80-71
Left Front Impact Sensor............ 8Wa-80-71
Left Front Park/Turn Signal Lamp..... 8Wa-80-71
Left Front Power Window Motor
(Midline/Highline)................ 8Wa-80-71
Left Front Wheel Speed Sensor (ABS) . . . 8Wa-80-72
Left Headlamp (Built-Up-Export)...... 8Wa-80-72
Left Headlamp (Except Built-Up-Export) . 8Wa-80-72
Left Heated Seat Assembly (Highline) . . . 8Wa-80-72
Left Heated Seat Switch (Highline)..... 8Wa-80-72
Left Instrument Panel Speaker........ 8Wa-80-73
Left Leveling Motor (Built-Up-Export) . . 8Wa-80-73
Left Position Lamp (Built-Up-Export) . . . 8Wa-80-73
Left Power Mirror (Except Base)....... 8Wa-80-73
8Wa - 80 - 2 8W-80 CONNECTOR PIN-OUTSKJ

Component Page
Sunroof Switch.................... 8Wa-80-95
Tailgate Cylinder Lock Switch......... 8Wa-80-95
Tailgate Flip-Up Ajar Switch.......... 8Wa-80-95
Tailgate Lock Motor/Ajar Switch....... 8Wa-80-95
Throttle Position Sensor............. 8Wa-80-96
Trailer Tow Brake Lamp Relay........ 8Wa-80-96
Trailer Tow Circuit Breaker.......... 8Wa-80-96
Trailer Tow Connector............... 8Wa-80-96
Trailer Tow Left Turn Relay.......... 8Wa-80-97Component Page
Trailer Tow Relay.................. 8Wa-80-97
Trailer Tow Right Turn Relay......... 8Wa-80-97
Transfer Case Position Sensor......... 8Wa-80-97
Transmission Control Module (3.7L).... 8Wa-80-98
Transmission Solenoid/TRS Assembly
(3.7L).......................... 8Wa-80-99
Washer Fluid Level Switch........... 8Wa-80-99
Washer Pump.................... 8Wa-80-100
Water In Fuel Sensor (Diesel)........ 8Wa-80-100
8Wa - 80 - 4 8W-80 CONNECTOR PIN-OUTSKJ

FUEL INJECTOR NO. 5 (3.7L) - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 F142 18OR/DG FUSED AUTO SHUT DOWN RELAY OUTPUT
2 K38 18GY FUEL INJECTOR NO. 5 DRIVER
FUEL INJECTOR NO. 6 (3.7L) - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 F142 18OR/DG FUSED AUTO SHUT DOWN RELAY OUTPUT
2 K58 18BR/DB FUEL INJECTOR NO. 6 DRIVER
FUEL PRESSURE SENSOR (DIESEL) - BLACK 3 WAY
CAV CIRCUIT FUNCTION
1 K80 20BK/VT FUEL PRESSURE SENSOR GROUND
2 K78 20GY FUEL PRESSURE SENSOR SIGNAL
3 K7 20OR FUEL PRESSURE SENSOR 5 VOLT SUPPLY
FUEL PRESSURE SOLENOID (DIESEL) - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 A142 14DG/OR AUTO SHUT DOWN RELAY OUTPUT
2 K46 18OR/BK FUEL PRESSURE SOLENOID CONTROL
FUEL PUMP MODULE - LT. GRAY 4 WAY
CAV CIRCUIT FUNCTION
1 Z211 16BK (GAS) GROUND
2 K4 18BK/LB SENSOR GROUND
3 K226 18DB/WT FUEL LEVEL SENSOR SIGNAL
4 A141 16DG/WT (GAS) FUEL PUMP RELAY OUTPUT
G 202 - BLACK 14 WAY
CAV CIRCUIT FUNCTION
1 Z12 16BK/TN GROUND
2 Z3 18BK/OR (BASE) GROUND
2 Z3 14BK/OR (EXCEPT BASE) GROUND
3 Z11 20BK/WT (EXCEPT BASE) GROUND
KJ8W-80 CONNECTOR PIN-OUTS8Wa-80-61

POWERTRAIN CONTROL MODULE-C2 (GAS) - WHITE 32 WAY
CAV CIRCUIT FUNCTION
13 - -
14 - -
15 K12 18TN FUEL INJECTOR NO. 2 DRIVER
16 K14 18LB/BR FUEL INJECTOR NO. 4 DRIVER
17 K173 18LG RADIATOR FAN RELAY CONTROL
18 - -
19 C18 18DB A/C PRESSURE SIGNAL
20 - -
21 - -
22 - -
23 G60 18GY/YL ENGINE OIL PRESSURE SENSOR SIGNAL
24 - -
25 - -
26 - -
27 - -
28 - -
29 - -
30 - -
31 K6 18VT/WT 5 VOLT SUPPLY
32 - -
POWERTRAIN CONTROL MODULE-C3 (GAS) - LT. GRAY 32 WAY
CAV CIRCUIT FUNCTION
1 C13 18DG A/C COMPRESSOR CLUTCH RELAY CONTROL
2- -
3 K51 18DB/YL AUTO SHUT DOWN RELAY CONTROL
4 V36 18TN/RD SPEED CONTROL VACUUM SOLENOID CONTROL
5 V35 18LG/RD SPEED CONTROL VENT SOLENOID CONTROL
6 K90 18TN (M/T) CLUTCH INTERLOCK RELAY CONTROL
7 K42 18DB/LB (3.7L) KNOCK SENSOR NO. 1 SIGNAL
7 K42 18DB/LB (2.4L) NOT USED
8 K99 18BR/OR OXYGEN SENSOR 1/1 HEATER CONTROL
9 K512 18RD/YL OXYGEN SENSOR DOWNSTEAM RELAY CONTROL
10 K106 18WT/DG LEAK DETECTION PUMP SOLENOID CONTROL
11 V32 18YL/RD SPEED CONTROL SUPPLY
12 F142 18OR/DG FUSED AUTO SHUT DOWN RELAY SENSE INPUT
13 T10 18YL/DG TORQUE MANAGEMENT REQUEST SENSE
14 K107 18OR LEAK DETECTION PUMP SWITCH SENSE
15 K118 18PK/YL BATTERY TEMPERATURE SENSOR SIGNAL
16 K299 18BR/WT (2.4L) OXYGEN SENSOR 1/2 HEATER CONTROL
16 K299 18BR/WT (3.7L) OXYGEN SENSOR 2/1 HEATER CONTROL
17 B22 18DG/YL VEHICLE SPEED OUTPUT
18 K142 18GY/BK (2.4L) NOT USED
18 K142 18GY/BK (3.7L) KNOCK SENSOR NO. 2 SIGNAL
19 K31 18BR FUEL PUMP RELAY CONTROL
20 K52 18PK/BK EVAP PURGE/SOLENOID CONTROL
21 - -
22 C21 18DB/OR A/C SWITCH SENSE
23 - -
24 K29 18WT/PK BRAKE LAMP SWITCH SENSE
25 K125 18WT/DB GENERATOR SOURCE
KJ8W-80 CONNECTOR PIN-OUTS8Wa-80-83

WASHER PUMP - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 V20 18BK/WT WASHER MOTOR SENSE
2 V10 18BR WASHER PUMP DRIVER
WATER IN FUEL SENSOR (DIESEL) - GRAY 2 WAY
CAV CIRCUIT FUNCTION
1 G123 20DG/WT WATER IN FUEL SENSOR SIGNAL
2 K4 18BK/LB SENSOR GROUND
8Wa - 80 - 100 8W-80 CONNECTOR PIN-OUTSKJ

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Coil On Plug No.5 (3.7L) BK Left Side of Engine Near
Fuel Injector No.51
Coil On Plug No.6 (3.7L) BK Right Side of Engine Near
Fuel Injector No.62
Coil Rail (2.4L) BK Right Side of Engine 11, 12
Combination Flasher WT Under Left Side of
Instrument PanelN/S
Compass Mini-Trip Computer BK At Overhead Console N/S
Controller Antilock Brake BK Left Side of Engine
Compartment30
Crankshaft Position Sensor (2.4L) BK Top of Engine N/S
Crankshaft Position Sensor (3.7L) BK Right Lower Side of Engine 4
Crankshaft Position Sensor (Diesel) BK Right Rear Side of Engine 17
Data Link Connector BK Under Center of Instrument
PanelN/S
Diagnostic Junction Port BK Under Center of Instrument
Panel49
Dome Lamp (Base) BK On Headliner N/S
Driver Airbag Squib 1 GY In Steering Wheel N/S
Driver Airbag Squib 2 BK In Steering Wheel N/S
Driver Seat Belt Switch LG At Drive Seat N/S
Driver Seat Belt Tensioner (LHD) YL Lower Left B-Pillar 35
Driver Seat Belt Tensioner (RHD) YL Lower Right B-Pillar 39
EGR Solenoid Right Rear Side of Engine
Compartment27
Engine Control Module C1 BK Left Rear Side of Engine
Compartment19
Engine Control Module C2 BK Left Rear Side of Engine
Compartment19
Engine Coolant Level Sensor (Diesel) LG Rear Side of Engine
Compartment18
Engine Coolant Temperature Sensor
(Diesel)BK Left Side of Engine 20
Engine Coolant Temperature Sensor
(Gas)BK Front Side of Engine 2
Engine Oil Pressure Sensor (2.4L) BK Top of Engine N/S
Engine Oil Pressure Sensor (3.7L) BK Left Front Side of Engine 3
Engine Oil Pressure Sensor (Diesel) BK Right Rear Side of Engine 17
Engine Starter Motor Right Front Side of Engine 20
Evap/Purge Solenoid BK At Solenoid N/S
Flip-Up Glass Release Motor BK In Tailgate 46
Flip-Up Glass Release Switch WT In Tailgate 46
Front Washer Pump BK Right Front Side of Engine
Compartment28
Front Wiper Motor (LHD) BK Left Side of Cowl 24
8Wa - 91 - 4 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONKJ
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Front Wiper Motor (RHD) BK Right Side of Cowl 24
Fuel Heater (Diesel) BK Left Rear Side of Engine
Compartment19
Fuel Injector No.1 (Diesel) BK At Fuel Injector 23
Fuel Injector No.1 (Gas) BK At Fuel Injector 1
Fuel Injector No.2 (Diesel) BK At Fuel Injector 23
Fuel Injector No.2 (Gas) BK At Fuel Injector 2
Fuel Injector No.3 (Diesel) BK At Fuel Injector 23
Fuel Injector No.3 (Gas) BK At Fuel Injector 1
Fuel Injector No.4 (Diesel) BK At Fuel Injector 22
Fuel Injector No.4 (Gas) BK At Fuel Injector 2
Fuel Injector No.5 (3.7L) BK At Fuel Injector 1
Fuel Injector No.6 (3.7L) BK At Fuel Injector 2
Fuel Pressure Sensor (Diesel) Left Side of Engine 22
Fuel Pressure Solenoid (Diesel) BK Left Side of Engine 20
Fuel Pump Module LG At Fuel Tank N/S
Generator BK Left Front Side of Engine 20
Glow Plug Assembly (Diesel) Top of Engine N/S
Headlamp Leveling Switch (BUX) BK Center of Instrument Panel N/S
Heated Seat Module (Highline) GN At Left Seat N/S
High Note Horn BK Left Front Side of Engine
Compartment29
Hood Ajar Switch Right Side of Engine
Compartment25
Idle Air Control Motor BK On Throttle Body 1
Ignition Switch At Steering Column N/S
Input Speed Sensor (3.7L) BK Left Side of Transmission 5
Instrument Cluster BK Rear of Cluster N/S
Intake Air Temperature Sensor GY Left Side of Intake Manifold 1
Intrusion Sensor (BUX) BK Overhead Console N/S
Junction Block Body Control Module -
JBUnder Left Side of
Instrument PanelN/S
Junction Block C1 GY Under Left Side of
Instrument PanelN/S
Junction Block C2 GN Under Left Side of
Instrument PanelN/S
Junction Block C3 LB Under Left Side of
Instrument PanelN/S
Knock Sensor (3.7L) BK Near Fuel Injector No.5 1
Leak Detection Pump BK Near Fuel Tank N/S
Left Curtain Airbag YL Left Mid B-Pillar 35, 38
Left Cylinder Lock Switch LG In Left Front Door 41
Left Door Lock Switch BK In Left Front Door 41
Left Fog Lamp BK Left Side of Front Bumper N/S
KJ8W-91 CONNECTOR/GROUND/SPLICE LOCATION8Wa-91-5
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION
Engine diagnosis is helpful in determining the
causes of malfunctions not detected and remedied by
routine maintenance.
These malfunctions may be classified as either per-
formance (e.g., engine idles rough and stalls) or
mechanical (e.g., a strange noise).
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING)ÐPERFORMANCE and (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)ÐMECHANICAL for
possible causes and corrections of malfunctions.
(Refer to 14 - FUEL SYSTEM/FUEL DELIVERY -
DIAGNOSIS AND TESTING) and (Refer to 14 -
FUEL SYSTEM/FUEL INJECTION - DIAGNOSIS
AND TESTING) for the fuel system diagnosis.Additional tests and diagnostic procedures may be
necessary for specific engine malfunctions that can
not be isolated with the Service Diagnosis charts.
Information concerning additional tests and diagno-
sis is provided within the following diagnosis:
²Cylinder Compression Pressure Test (Refer to 9 -
ENGINE - DIAGNOSIS AND TESTING).
²Cylinder Combustion Pressure Leakage Test
(Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING).
²Engine Cylinder Head Gasket Failure Diagnosis
(Refer to 9 - ENGINE/CYLINDER HEAD - DIAGNO-
SIS AND TESTING).
²Intake Manifold Leakage Diagnosis (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
DIAGNOSIS AND TESTING).
DIAGNOSIS AND TESTING - ENGINE DIAGNOSIS - PERFORMANCE
CONDITION POSSIBLE CAUSE CORRECTION
ENGINE WILL NOT START 1. Weak battery 1. Charge or replace as necessary.
2. Corroded or loose battery
connections.2. Clean and tighten battery
connections. Apply a coat of light
mineral grease to the terminals.
3. Faulty starter. 3. (Refer to 8 - ELECTRICAL/
STARTING - DIAGNOSIS AND
TESTING).
4. Faulty coil or control unit. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
5. Incorrect spark plug gap. 5. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING).
6. Incorrect right bank cam timing. 6. Refer to engine timing in this
section.
7. Dirt or water in fuel system. 7. Clean system and replace fuel
filter.
8.Faulty fuel pump, relay or wiring. 8.Repair or replace as necessary.
9. Faulty cam or crank sensor 9. Refer to Ignition system.
ENGINE STALLS OR ROUGH IDLE 1. Vacuum leak. 1. Inspect intake manifold and
vacuum hoses, repair or replace as
necessary.
2. Faulty crank position sensor 2. Replace crank position sensor.
4. Faulty coil. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
9 - 4 ENGINE - 3.7LKJ
ENGINE - 3.7L (Continued)

CONDITION POSSIBLE CAUSE CORRECTION
5. Incorrect cam timing. 5. (Refer to 9 - ENGINE/VALVE
TIMING - STANDARD
PROCEDURE).
1. ENGINE LOSS OF POWER 1. Dirty or incorrectly gapped spark
plugs.1. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING).
2. Dirt or water in fuel system. 2. Clean system and replace fuel
filter.
3. Faulty fuel pump. 3. (Refer to 14 - FUEL SYSTEM/
FUEL DELIVERY/FUEL PUMP -
DIAGNOSIS AND TESTING).
4. Blown cylinder head gasket. 4. Replace cylinder head gasket.
5. Low compression. 5. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING), repair
as necessary.
6. Burned, warped or pitted valves. 6. Replace as necessary.
7. Plugged or restricted exhaust
system.7. Inspect and replace as
necessary.
8. Faulty coil. 8. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
9. Incorrect cam timing. 9. Refer to Engine TIming in this
section.
1. ENGINE MISSES ON
ACCELERATION1. Spark plugs dirty or incorrectly
gapped.1. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING).
2. Dirt in fuel system. 2. Clean fuel system.
3. Burned, warped or pitted valves. 3. Replcae as necessary.
4. Faulty coil. 4. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
1. ENGINE MISSES AT HIGH
SPEED1. Spark plugs dirty or incorrectly
gapped.1. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/SPARK PLUG
- CLEANING).
2. Faulty coil. 2. (Refer to 8 - ELECTRICAL/
IGNITION CONTROL/IGNITION
COIL - REMOVAL).
3. Dirt or water in fuel system. 3. Clean system and replace fuel
filter.
KJENGINE - 3.7L 9 - 5
ENGINE - 3.7L (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
OIL PUMPING AT RINGS; SPARK
PLUGS FOULING1. Worn or damaged rings. 1. Hone cylinder bores and replace
rings.
2. Carbon in oil ring slots. 2. Replace rings (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON
RINGS - STANDARD
PROCEDURE).
3. Incorrect ring size installed. 3. Replace rings (Refer to 9 -
ENGINE/ENGINE BLOCK/PISTON
RINGS - STANDARD
PROCEDURE).
4. Worn valve guides. 4. Ream guides and replace valves
(Refer to 9 - ENGINE/CYLINDER
HEAD/INTAKE/EXHAUST VALVES
& SEATS - STANDARD
PROCEDURE).
5. Leaking valve guide seals. 5. Replace valve guide seals.
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE
The results of a cylinder compression pressure test
can be utilized to diagnose several engine malfunc-
tions.
Ensure the battery is completely charged and the
engine starter motor is in good operating condition.
Otherwise the indicated compression pressures may
not be valid for diagnosis purposes.
(1) Clean the spark plug recesses with compressed
air.
(2) Remove the spark plugs.
(3) Secure the throttle in the wide-open position.
(4) Disable the fuel system (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY - DESCRIPTION).
(5) Remove the ASD relay (Refer to 8 - ELECTRI-
CAL/IGNITION CONTROL/AUTO SHUT DOWN
RELAY - REMOVAL).
(6) Insert a compression pressure gauge and rotate
the engine with the engine starter motor for three
revolutions.
(7) Record the compression pressure on the 3rd
revolution. Continue the test for the remaining cylin-
ders.
(8) (Refer to 9 - ENGINE - SPECIFICATIONS) for
the correct engine compression pressures.
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing).²Leaks between adjacent cylinders or into water
jacket.
²Any causes for combustion/compression pressure
loss.
(1) Check the coolant level and fill as required. DO
NOT install the radiator cap.
(2) Start and operate the engine until it attains
normal operating temperature, then turn the engine
OFF.
(3) Remove the spark plugs.
(4) Remove the oil filler cap.
(5) Remove the air cleaner.
(6) Calibrate the tester according to the manufac-
turer's instructions. The shop air source for testing
should maintain 483 kPa (70 psi) minimum, 1,379
kPa (200 psi) maximum and 552 kPa (80 psi) recom-
mended.
(7) Perform the test procedures on each cylinder
according to the tester manufacturer's instructions.
Set piston of cylinder to be tested at TDC compres-
sion,While testing, listen for pressurized air escaping
through the throttle body, tailpipe and oil filler cap
opening. Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal,
with no more than 25% leakage.
FOR EXAMPLE:At 552 kPa (80 psi) input pres-
sure, a minimum of 414 kPa (60 psi) should be main-
tained in the cylinder.
Refer to CYLINDER COMBUSTION PRESSURE
LEAKAGE DIAGNOSIS CHART .
9 - 8 ENGINE - 3.7LKJ
ENGINE - 3.7L (Continued)