coolant temperature ISUZU TROOPER 1995 User Guide

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
•

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

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

1••1 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
• Disconnect from vacuum pipe.
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.
Canister vacuum hose
• Disconnect from common chamber.
15.
Exhaust Gas Recirculation Valve assembly
• Remove five bolts from common chamber,
exhaust manifold and cylinder head cover.
16.
Common chamber duct
• Remove four bolts, four nuts and three bracket
fixing bolts, then remove the
common
chamber.
• Disconnect ground cable from rear side of
common chamber.
ENGINE (V6 3.2L DOHC AND SOHC) 6A1 47
17. Throttle body
• Disconnect Engine Coolant hose from throttle
body.
• Disconnect Idle Air Control Valve and Throttle
Position Sensor connectors.
18.
Common chamber
• Remove six bolts and two nuts.
• Remove fixing bolts on common chamber
bracket, then the
common chamber.
19.
Fuelhoses
• Disconnect feed and return fuel hoses from fuel
pipes, and remove
two bracket fixing bolts on
the cylinder head cover.
20. Fuel injector connectors
• Disconnect connectors from injectors.
• Disconnect thermo sensor connector.
21.
Intake manifold
• Remove two fixing bolts and four nuts.
22. Engine
Coolant manifold
• Disconnect heater hose.
• Remove four fixing bolts.
23.
Power steering pump drive belt
24. Air Conditioning compressor drive belt
25. Generator drive belt
26. Power steering pump
27. Fan pulley assembly
28. Crankshaft pulley assembly
I®J • Using special tool J-8614-01, hold crankshaft
pulley.
•
Remove center bolt, then the pulley.
29. Oil cooler hose
• Remove two cooler hose bracket fixing bolts on
the timing belt cover.
30. Timing belt cover
31. Pusher
CAUTION:
The pusher prevents air from entering the oil
chamber. Its rod must always be facing upward.
32.
Timing belt
w CAUTIONS:
' 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.

68 - 2 ENGINE COOLING
The cooling system is a pressurized Engine Coolant
(EC) forced circulation type which consists of water
pump, thermostat cooling fan, radiator and other
components. The automatic transmission fluid is
cooled by the EC in radiator.
WATER PUMP
Fig. 68-2
The
EC pump is a centrifugal impeller type and is
driven by timing belt. (Fig.68-2)
THERMOSTAT
Jiggle valve
Fig. 68-3
The
thermostat is a wax pellet type with a jiggle
valve and is installed in the thermostat housing.
(Fig.68-3)
RADIATOR
The radiator is a tube type with corrugated fins. In
order to raise the boiling point of coolant, the radiator
is fitted
with a cap in which the valve is operated at
88.2
-117.6 kPa (12.8 - 17.0 psi) pressure. (No oil
cooler
provided for M!f)
Fig. 68-4
ANTI-FREEZE SOLUTION
•
•
Relation between Mixing ratio and Freezing
temperature
of the EC varies with the ratio of
anti-freeze solution in water. Proper mixing
ratio can be determined by referring to the
chart. Supplemental inhibitors or additives
claiming to increase cooling capability that have
not been specifically approved by lsuzu are not
recommended for addition to the cooling
system.
Calculation mixing ratio (Fig. 68-5)
Mixing ratio
Anti-freese
solution (Lit/gal.) =-----------------Anti-freese solution (Lit/gal.) +Water (Lit/gal.)
Note: Anti-freeze solution +Water=
Total cooling system capacity.
Lit (Us
gal)
Total Cooling
M!f 8.5 (2.24) ~-~~--------System Capacity AfT 8.8 (2.32)

Mixing ratio(%) 0 10 20 30 40 50
~
' -10
'
1
' -30

~ -40
In case of 8.5 lit total cooling system capacity
Mixing Anti-freeze
Water: solution: ratio (%) lit. (U.S. gal) lit. (U.S. gal.)
0 0 0
8.5 (2.2) 10 0.9 (0.3) 7.6 (2.0) 15
1.3 (0.4) 7.2 (1.9) 20 1.7 (0.5) 6.8 (1.8)
25 2.1 (0.6) 6.4 (1.7) 30 2.6 (0.7) 5.9 (1.6)
35 3.0 (0.8) 5.5
(1.5) 40 3.4 (0.9) 5.1 (1.3)
45 3.8 (1.0) 4.7 (1.2) 50 4.3 (1.1)
4.2 (1.1)
Fig. 68-5
ENGINE COOLING 68-3
• Mixing ratio
Check
the specific gravity of engine coolant in the
cooling system temperature ranges from oo C to
50° C using a suction type hydrometer, then deter­
mine the densityofthe Engine Coolant by referring
to the table. (Fig. 68-6)
1,100 1'-........ ........ ...... .............. Mixing ratio
~"""--r-... 1'-""' 1,1)90
........ ...... ........ ........ .......... '
1,000
'"" 1,07 o......_ 1'-........ I'-.......... I"-........ .......
I"-........ ..........
................. I"-........
'
1,080
....... I"-........ ~ ........ ......
........ "'" ~"""--r--..... 1,050
r-. ........ ~ .......... ......
---
........ ........ 1,040
r-.... !'--.. 1'-0 '"" ~"""--1'-.... ........ 1,03
1--....... ........ r--~ ........
'
1,020
....... ~ 1'-0 ~"""---.... 1,01
...... ,
'
1,000
10 20 30 40 50 60 70 Coolant temperature ("C)
Fig. 68-6
DIAGNOSIS
ENGINE COOLING TROUBLE
Condition Possible cause Correction
Engine
overheating Low Engine Coolant level Replenish
Thermo unit faulty Replace
Faulty
thermostat Replace
Faulty
Engine Coolant unit Repair or replace
Clogged
radiator Clean or replace
Faulty
radiator cap Replace
Low engine oil level or use of improper Replenish or change oil
engine oil
Clogged exhaust system Clean exhaust system or replace
faulty parts
Faulty Throttle Position sensor Replace throttle valve assembly
Open or shorted Throttle Position sensor circuit Repair or replace
Damaged cylinder head gasket Replace
Engine overcooling Faulty thermostat Replace
Engine slow to Faulty thermostat Replace
warm-up Thermo unit faulty Replace

68-6 ENGINE COOLING
THERMOSTAT
Removal steps
1. Inlet pipe
2. Packing
3. Thermostat
Installation steps
To
install, follow the removal steps in the reverse order.
Fig. 68-9
B REMOVAL
Preparation
• Disconnect battery ground cable.
•
Drain Engine Coolant from the radiator and
engine.
• Disconnect radiator hose from the inlet pipe.
1. Inlet pipe
2. Packing
3.
Thermostat
~ INSPECTION
Suspend the thermostat in a water-filled container
using thin wire. Place a thermometer next to the
thermostat.
Do not directly heat the thermostat.
Gradually increase the water temperature. Stir the
water so that the entire water is same temperature.
(Fig.68-10)
Confirm the temperature when the valve first
begins to open.
Valve opening temperature oc
(oF)
74.5-78.5
( 166.1 -173.3)
Confirm the temperature when the valve is fully
opened.
Valve full open temperature oc
and lift (°F)
More than 10mm
(0.39 in) at 90°C
(194°F)
Make necessary repair and parts
replacement if
extreme wear or damage is found during
inspection.
Fig.
68-10
Fig. 68-10
•

E!) INSTALLATION
6. Radiator assembly
• Install cushion rubbers on both sides of radia­
tor bottom.
• Install radiator assembly with hose, taking
care
not to damage the radiator core with a fan
blade.
5. Bracket
• Support the radiator uppertankwith the bracket
and secure the radiator.
4. Reserve tank hose
3. Fan guide, lower
2. Radiator hose
• Connect inlet hose and outlet hose to the
engine.
1. Oil cooler hose (A/T)
• Connect oil cooler hose for automatic trans-
mission.
• Connect battery ground cable.
• Pour engine coolant.
• Pour engine coolant up to filler neck of radia­
tor, and up to MAX mark of reserve tank. (Fig.
68-16)
Reserve tank
Fig. 68-16
ENGINE COOLING 68-9
U7 Important operation (in case of 100% Engine
V Coolant change) procedure for filling with
Engine Coolant
• Fill
with Engine Coolant (EC) to the radiator
filler neck.
• Fill with EC to the "MAX" line on the reservoir.
• Start the engine with the radiator cap removed
and bring
to operating temperature by running
engine at
2,500-3,000 revolution per minute
for 30 minutes.
• By EC temperature gauge reading make sure
that the thermostat is open.
• If air bubbles come up to the radiator filler
neck, replenish with EC repeat until the EC
level does not drop any further. Install the
radiator cap and stop the engine.
• Replenish EC to the "MAX" line on the reser­
voir and leave as it is until the engine gets cool.
• After the engine gets cool, start the engine and
make sure there is no
water running noise
heard
from the heater core while the engine
runs
at 3000 revolution per minute.
• Should water running noise be heard, repeat
the same procedure from the beginning.

68 -12 ENGINE COOLING
MAIN DATA AND SPECIFICATIONS
M!T I AfT
Cooling system
Engine Coolant forced circulation
Radiator (1 tube in row) Tube type corrugated (2 tube in row)
Heat radiation capacity
kcal/h 58000
I
76000
Heat radiation area m2 (ft2)
8.443 (0.785) 15.631 (1.454)
Front area m2 (ft2) 0.309 (0.029)
Dry weight kg (lb) 4.2 (9.5) I 7.4 (16.3)
Radiator cap
Valve opening pressure kPa(psi) 88.2-117.61(12.8-17.0)
Radiator coolant capacity lit (U.S q.t.) 2.1 (2.2) 2.4 (2.5)
Engine
coolant pump Centrifugal impeller type
Delivery lit(U.S qt)/min 300 (317) or more
Pump speed rpm 5000 ±50
Thermostat Wax pellet type with jiggle valve
Valve
opening temperature oc (oF) 74.5-78.5 (166.1-169.7)
Engine
coolant total capacity lit (U.S qt) 8.5 (9.0) I 8.8
(9.3)
TORQUE SPECIFICATIONS N-m (lb·ft)
Fig. 68-18
..