sensor ISUZU TROOPER 1995 Manual Online

6-8 ENGINE DIAGNOSIS
ENGINE LACKS POWER
Condition
Possible cause Correction
Trouble in fuel system Fuel Pressure Control Valve not Replace
working normally
Fuel
injector clogged Clean or replace
Fuel
pipe clogged Clean
Fuel filter clogged
or fouled Replace
Fuel
pump drive circuit not working Correct or replace
normally
Fuel tank not sufficiently breathing due Clean or replace
to clogged Evaporative Emission
Control System circuit
Water in
fuel system Clean
Inferior quality fuel
in fuel system Use fuel of specified octane
rating
Engine
Control Module supplied poor Correct circuit
voltage
Throttle
Position Sensor cable Correct or replace
disconnected or broken
Throttle Position Sensor defective Replace
Manifold Absolute
Pressure Sensor not Replace
working normally
Intake Air Temperature Sensor not Replace
working normally
Engine Coolant Temperature Sensor Correct or replace
circuit open or shorted
Engine
Coolant Temperature Sensor Replace
defective
Engine
Control Module defective Replace
Trouble
in intake or exhaust Air Cleaner Filter clogged Replace filter element
system Trouble in Induction air control valve Correct or replace
system (DOHC)
Air duct kinked or flattened Correct or replace
Ignition failure
Refer to Hard Start
Troubleshooting Guide
Heat range
of spark plug inadequate Install spark plugs of adequate
heat range
Electronic Ignition System with module Replace
•

ENGINE DIAGNOSIS 6-9
ENGINE LACKS POWER (Cont'd)
Condition Possible cause Correction
Engine overheating
Level of Engine Coolant too low Replenish
Thermo switch or fan motor defective Replace
Thermostat defective Replace
Engine
Coolant pump defective Correct or replace
Radiator clogged
Clean or replace
Radiator
filler cap defective Replace
Level
of oil in engine crankcase too low Change or replenish
or
wrong oil engine
Resistance in exhaust system
Clean exhaust system or
increased replace
defective parts
Throttle Position Sensor adjustment Adjust
Wide Open Throttle
incorrect switch setting
Throttle Position Sensor circuit open
or Correct or replace
shorted
Cylinder head gasket damaged Replace
Engine overcooling
Radiator
overcooling Install cover
in front of
radiator
Thermostat defective Replace
(Use a thermostat set
to open at a2·c (180.F))
Engine
lacks compression Refer to Hard Start
Others Tire inflation pressure
abnormal Adjust to recommend
pressures
Brake drag Adjust
Clutch slipping Adjust or replace
Level
of oil in engine crankcase too Correct level of engine oil
high
Exhaust Gas
Recirculation Valve Replace
defective
Back pressure transducer defective
Replace

6-12 ENGINE DIAGNOSIS
ABNORMAL COMBUSTION
Condition
Possible cause Correction
Trouble in fuel Fuel pressure control valve defective Replace
injection system
Fuel filter clogged
Replace
Fuel pump clogged Clean or replace
Fuel tank
or fuel pipe clogged Clean or replace
Fuel injector clogged Clean or replace
Fuel
pump relay defective
Replace
Power supply cable for fuel pump loosely connected or Reconnect, correct or
defective
replace
Manifold Absolute
Pressure Sensor circuit open or shorted Correct or replace
Manifold Absolute
Pressure Sensor defective Replace
Engine Coolant Temperature
(ECT) Sensor circuit open or Correct or replace
shorted
ECT Sensor defective
Replace
Throttle
Position Sensor adjustment incorrect Replace throttle valve
Throttle
Position Sensor defective
Replace
Throttle
Position Sensor connector loosely connected Reconnect
Vehicle Speed Sensor cable loosely connected or Correct or replace
defective
Vehicle Speed Sensor loosely fixed Fix tightly
Vehicle Speed Sensor in wrong contact or defective Replace
Engine Control Module cable
loosely connected or Correct or replace
defective
Trouble in emission
Heated
Oxygen Sensor circuit open Correct or replace
control system
Heated
Oxygen Sensor defective Replace
Vacuum Switch
Valve (VSV); Replace
Exhaust Gas Recirculation defective
Signal vacuum hose loosely fitted or defective Correct or replace
Exhaust Gas Recirculation
Valve defective Replace
Back
Pressure Transducer defective Replace
ECT Sensor circuit open or shorted Correct or replace
ECT Sensor defective Replace
Pressure Control Valve (PCV) and hose clogged Correct or replace
Evaporator system
Refer
to Section 6E
Trouble in ignition
Refer to "Engine
system Lacks
Power"
Trouble in cylinder
Carbon deposits in combustion chamber Remove carbon
head parts
Carbon deposit on valve,
valve seat and valve guide
Remove carbon
•

ENGINE DIAGNOSIS 6-15
MALFUNCTION INDICATOR LAMP
The instrument panei"CHECK ENGINE" Malfunction Indicator Lamp (MIL) illuminates by self diagnostic
system
when the system checks the bulb at the starting of engine, or senses malfunctions.
Complaint
Faulty parts
"CHECK
ENGINE" MIL
does not
illuminate
at the starting
of engine
"CHECK Heated Oxygen
ENGINE" MIL Sensor
illuminates,
and stays on
Engine
Coolant
Temperature Sensor
Throttle Position
Sensor
Crankshaft Position Sensor
Vehicle Speed
Sensor
Manifold
Absolute
Pressure Sensor
Intake Air
Temperature Sensor
Fuel Injector
ECM
Note: *1
-Random Access Memory
*2
-Read Only Memory
Possible cause Correction
Bulb defective Replace
MIL
circuit open Correct or replace
Command signal
circuit to operate self Correct or replace
diagnostic system shorted
Engine
Control Module (ECM) cable Correct or replace
loosely
connected, disconnected or
defective
ECM defective Replace
Deterioration of internal element Replace
Connector terminal improper contact Reconnect properly
Lead wire shorted Correct
Circuit
open Correct or replace
Deterioration of internal element Replace
Connector terminal improper contact Reconnect properly
Lead wire shorted Correct
Circuit
open Correct or replace
Open
or shorted circuits Correct or replace
Deterioration of sensor Replace
Open
or shorted circuit Correct or replace
Open
circuit Correct or replace
Open
or shorted circuit Correct or replace
Open
or shorted circuit Correct or replace
Open
or shorted circuit Correct or replace
Driver transistor defective Replace ECM
RAM*1 or ROM*2 malfunctioning Replace ECM

6A1-8 ENGINE (V6 3.2L DOHC AND SOHC)
COMMON CHAMBER DUCT (DOHC)
8
11
5
5
6
7
14
5 5
Fig. 6A1-9
E) REMOVAL
Preparation: Battery ground cable
1. Air cleaner assembly
2. Accelerator pedal cable
• Disconnect from throttle body and cable
bracket.
3. Canister vacuum hose
• Disconnect from Vacuum Switch Valve (VSV).
4. Vacuum booster hose
• Disconnect from common chamber.
5. Connectors
• Disconnect from Idler Air Control Valve, Throttle
Position Sensor, Manifold Absolute Pressure,
canister VSV, Exhaust Gas Recirculation (EGR)
VSV, Intake Air Temperature and vacuum tank
vsv.
6. High tension cables
• Disconnect from cylinder head cover.
7. Ignition Control Module assembly
• Disconnect three Electronic Ignition
connectors.
• Remove three Electronic Ignition bracket fixing
bolts, and remove Electronic Ignition assembly
with plug wires.
8. Throttle Body
• Remove four fixing bolts.
9. Vacuum hoses
• Disconnect vacuum hoses on canister VSV and
EGR VSV from the throttle body.
10. Fuel Pressure Control Vavle vacuum hose
• Disconnect from common chamber duct.
11. Positive Crankcase Ventilation hose
• Disconnect from common chamber duct.
12. Evaporative Emission Canister Purge hose
• Disconnect from common chamber duct.
13. EGR Valve assembly
• Remove EGR Valve assembly and four pipe
fixing bolts from common chamber duct and
exhaust manifold.
14. Common chamber duct
• Remove four bolts and nuts and three bracket
fixing bolts.
• Remove the common chamber duct.
l·u·IINSTALLATION
14. Common chamber duct
• Tighten bolts and nuts to the specified torque.
Bolts
~~~ Torque N·m (lb·ft) 24 (17)
•

1"!
6A 1-12 ENGINE (V6 3.2L DOHC AND SOHC)
COMMON CHAMBER (DOHC)
Fig. 6A1-13
l•+l REMOVAL
Preparation: Battery ground cable
1. Air cleaner assembly
2. Accelerator Pedal cable
• Disconnect from throttle body and cable
bracket.
3. Canister vacuum hose
• Disconnect from Vacuum Switching Valve
(VSV).
4.
Vacuum booster hose
• Disconnect from common chamber.
5. Connectors
• Disconnect from Idle Air Control Valve, Throttle
Position Sensor, Manifold Absolute Pressure,
canister VSV, Exhaust Gas Recirculation (EGR)
VSV, Intake Air Temperature and vacuum tank
vsv.
6. High tension cables
•
Disconnect from cylinder head cover.
7. Ignition Control Module assembly
• Disconnect three Electronic Ignition
connectors.
• Remove three Electronic Ignition bracket fixing
bolts, and remove Electronic Ignition assembly
with plug wires.
8. Throttle body
• Remove four fixing bolts.
9. Vacuum hoses
• Disconnect vacuum hoses on canister VSV and
EGR VSV from the throttle body.
10. Fuel Pressure Control Valve vacuum hose
• Disconnect from common chamber duct.
11.
Positive Crankcase Ventilation hose
• Disconnect from common chamber duct.
12.
Evaporative Emission Canister Purge hose
• Disconnect from common chamber duct.
13.
EGR Valve assembly
• Remove EGA Valve assembly and four pipe
fixing
bolts from common chamber duct and
exhaust
manifold.
14. Common chamber duct
• Remove four bolts and nuts and three bracket
fixing
bolts.
•
Remove the common chamber duct.
15.
Throttle body
• Disconnect water hose from Throttle Body. At
this time, pinch the hose with pinch-off pliers to
prevent water leakage.
16. Common chamber
• Remove six bolts and two nuts. ~
• Remove common chamber fixing bolts on the
rear side
of common chamber, then remove
common chamber.
1111

6A1-14 ENGINE (V6 3.2L DOHC AND SOHC)
INTAKE MANIFOLD (SOHC}
13 10
7
6
14
4 15
Fig. 6A1-15
1••1 REMOVAL
Preparation: Battery ground cable
1. Air cleaner assembly
2. Accelerator Pedal cable
• Disconnect from throttle body and cable
bracket.
3. Vacuum booster hose
• Disconnect from common chamber.
4. Connectors
• Disconnect from Manifold Aboslute Pressure,
canister Vacuum Switching Valve (VSV),
Exhaust
Gas Recirculation VSV, Intake Air
Temperature and ground cable.
5. High tension cables
• Disconnect from cylinder head cover.
6. Ignition Control Module assembly
• Disconnect three Electronic Ignition con­
nectors.
• Remove three Electronic Ignition bracket fixing
bolts, and remove Electronic Ignition assembly
with plug wires.
7. Throttle body
• Remove four fixing bolts.
8. Vacuum hoses
• Disconnect vacuum hoses on canister VSV and
Exhaust Gas Recirculation VSV
from the throttle
body.
9. Positive Crankcase Ventilation hose
• Disconnect from common chamber.
10. Fuel Pressure Control Valve vacuum hose
• Disconnect from common chamber.
11. Evaporative Emission Canister Purge hose
• Disconnect from common chamber.
12. Exhaust Gas Recirculation Valve assembly
• Remove two bolts from common chamber and
disconnect Backpressure Transducer vacuum
hose.
13. Common chamber
• Remove six bolts and two nuts and three
bracket fixing bolts.
• Remove the common chamber.
14. Fuel hoses
• Disconnect feed and return fuel hoses from fuel
pipes, and remove two bracket fixing bolts on
the cylinder head cover.
15. Connectors
• Disconnect connectors for each fuel injector.
• Disconnect thermo sensor connector.
•

.,
6A1-16 ENGINE (V6 3.2L DOHC AND SOHC}
INTAKE MANIFOLD (DOHC)
Fig. 6A1-17
1••1 REMOVAL
Preparation: Battery ground cable
1. Air cleaner assembly
2. Accelerator Pedal cable
• Disconnect from throttle body and cable
bracket.
3. Canister vacuum hose
• Disconnect from Vacuum Switching Valve
(VSV).
4. Vacuum booster hose
• Disconnect from common chamber.
5. Connectors
• Disconnect from Idle Air Control Valve, Throttle
Position Sensor, Manifold Absolute Pressure,
canister
VSV, Exhaust Gas Recirculation (EGR)
VSV, Intake Air Temperature and vacuum tank
vsv.
6. High tension cables
• Disconnect from cylinder head cover.
7. Ignition Control Module assembly
• Disconnect three Electronic Ignition con­
nectors.
• Remove three Electronic Ignition bracket fixing
bolts, and remove Electronic Ignition assembly
with plug wires.
8. Throttle body
• Remove four fixing bolts.
9. Vacuum hoses
• Disconnect vacuum hoses on canister VSV and
EGR VSV from the throttle body.
10. Fuel Pressure Control Valve vacuum hose
• Disconnect from common chamber duct.
11. Positive Crankcase Ventilation hose
• Disconnect from common chamber duct.
12. Evaporative Emission Canister Purge hose
• Disconnect from common chamber duct.
13. EGR Valve assembly
• Remove EGR Valve assembly and four pipe
fixing
bolts from common chamber duct and
exhaust
manifold.
14. Common chamber duct
• Remove four bolts and nuts and three bracket
fixing
bolts.
•
Remove the common chamber duct.
15. Throttle body
• Disconnect water hose from throttle body. At
this time, pinch the hose with pinch-off pliers to
prevent water leakage.
16. Common chamber
• Remove six bolts and two nuts.
• Remove common chamber fixing bolts on the
rear side
of common chamber, then remove
common chamber.
•

EJ REMOVAL
Preparation: • Remove engine hood.
• Drain radiator Engine Coolant.
• Disconnect battery ground cable.
1. Air cleaner assembly
2. Radiator upper fan shroud
• Remove from radiator.
3. Radiator fan assembly
• Remove four nuts, then the radiator fan
assembly.
4. Accelerator Pedal cable
• Disconnect from throttle body and cable
bracket.
5. Canister vacuum hose
6. Vacuum booster hose
• Disconnect from common chamber.
7. Connectors
• Disconnect from Manifold Absolute Pressure,
canister Vacuum Switching
Valve (VSV),
Exhaust Gas Recirculation VSV,
Intake Air
Temperature and ground cable.
8. High tension cables
• Disconnect from cylinder head cover.
9. Ignition Control Module assembly
• Disconnect three Electronic Ignition con­
nectors.
• Remove three Electronic Ignition bracket fixing
bolts, and remove Electronic Ignition assembly
with high tension cables.
10. Throttle body
• Remove four fixing bolts.
11. Vacuum hoses
• Disconnect vacuum hoses on canister VSV and
Exhaust Gas Recirculation VSV
from the
throttle body.
12. Positive Crankcase Ventilation hose
• Disconnect from common chamber.
13. Fuel Pressure Control Valve vacuum hose
• Disconnect from common chamber.
14. Evaporative Emission Canister Purge hose
• Disconnect from common chamber.
15. Exhaust Gas Recirculation assembly
16. Common chamber
• Remove six bolts, two nuts and four bracket
fixing bolts, then remove the
common
chamber.
17. Throttle body
• Disconnect Engine Coolant hose from throttle
body.
• Disconnect Idler Air Control Valve and Throttle
Position Sensor connectors.
ENGINE (V6 3.2L DOHC AND SOHC) 6A1-43
18. Fuelhoses
• Disconnect feed and return fuel hoses from fuel
pipes, and remove two bracket fixing bolts on
the cylinder head cover.
19. Fuel injector connectors
• Disconnect connectors from injectors.
• Disconnect thermo sensor connector.
20. Intake manifold
• Remove two fixing bolts and four nuts.
21. Engine Coolant manifold
• Disconnect heater hose.
• Remove four fixing bolts.
22. Power steering pump drive belt
23. Air Conditioning compressor drive belt
24. Generator drive belt
25. Power steering pump
26.
Fan pulley assembly
27. Crankshaft pulley assembly
~ • Using special tool J-8614-01, hold crankshaft
~ pulley.
•
Remove center bolt, then the pulley.
28. Oil cooler hose
• Remove two cooler hose bracket fixing bolts on
the timing
belt cover.
29. Timing belt cover
30. Pusher
\fl CAUTION:
VI The pusher prevents air from entering the oil
chamber. Its rod must always be facing upward.
31. Timing belt
\fl CAUTIONS:
VI 1) Do not bend or twist the belt, otherwise its
core
could be damaged. The belt should not
be bent at a radius less than 30mm.
2) Do not allow oil or other chemical substances
to come in contact with the belt. They will
shorten the belt life.
3) Do not attempt to pry or stretch the belt with a
screwdriver
or any other tool during
installation.
4) Store timing belt in a cool and dark place.
Never expose the
belt to direct sunlight or
heat.
32. Cylinder head cover
• Remove 11 fixing bolts, then the cylinder head
cover.
33. Power steering pump bracket
• Disconnect ground cable from bracket.
• Remove five fixing bolts, then the bracket.
34. Exhaust front pipe
35.
Level gage guide tube fixing bolt
• Remove from cylinder head.
36. Cylinder head

16. Common chamber
~~~· Tighten bolts and nuts to the specified torque.
Bolts
Torque N·m (lb·ft) 24 (17)
Nuts
Torque
N·m (lb·ft) 24 (17)
15. Exhaust Gas Recirculation Valve assembly
• Tighten bolts to the specified torque.
Exhaust Gas
Recirculation Valve Side
~~~ Torque N·m (lb·in) I 8 (69)
Exhaust Manifold Side
~~~ Torque N·m (lb·ft) 28 (21)
14. Evaporative Emission Canister Purge hose
13.
Fuel Pressure Control Valve vacuum hose
12. Positive
Crankcase Ventilation hose
11.
Throttle body
~~~· Tighten bolts to the specified torque.
Torque
N·m (lb·ft) I 19 (14)
10. Vacuum hoses
• Connect vacuum hoses on canister Vacuum
Switching Valve and Exhaust Gas Recirculation
Vacuum
Switching Valve to the throttle body.
• Connect Engine Coolant hose and also connect
Idler Air Control Valve and Throttle Position
Sensor connectors.
9. Ignition Control Module assembly
~ • Tighten bolts to the specified torque
~ connect connector. and
Torque
N·m (lb·ft) 19 (14)
8. High tension cables
7. Connectors
• Connect each connector without fail.
6. Vacuum booster hose
5. Canister vacuum hose
ENGINE (V6 3.2L DOHC AND SOHC) 6A 1-45
4. Accelerator Pedal cable
• Accelerator pedal cable adjustment (Fig. 6A 1-
54)
1) Loosen the adjusting nut and screw cap.
2) Pull outer cable while fully closing the
throttle valve.
3) Tighten adjusting nut and screw cap
temporarily.
4) Loosen adjusting nut by three turns and
tighten
screw cap.
Then,
manually operating the throttle
valve, make sure that the valve lever
returns up to the stopper screw. If it does
not reach the stopper screw, repeat
from
step 1 ).
@:Screw cap
@ : Adjusting nut
Fig. 6A1-54
3. Cooling fan assembly
~~~· Tighten fixing bolts to the specified torque.
Torque
N·m (lb·in) I 8 (69)
2. Radiator upper fan shroud
1. Air cleaner assembly
NOTE:
• After installation refill the engine coolant. Refer
to Section 68 "Engine cooling".