engine ISUZU TROOPER 1998 Service Repair Manual

6B Ð 12 ENGINE COOLING
TENSION ADJUSTMENT
P/S oil pump and A/C compressor pulley belt.
·With P/S pump lock bolt loose, adjust belt tension
with adjust belt.
Cooling fan pulley belt
·With AC Generator mounting and lock bolts loose,
adjust belt tension with adjuster's adjust bolt.
AC generator fixing bolt40 (4.1/30) Torque StandardN·m(Kg·m/lb·ft)
Adjust plate fixing bolt24 (2.4/17)
Adjust plate lock bolt19 (1.9/14)
P/S oil pump adjustor lock bolt37 (3.8/27)

6C Ð 6 FUEL SYSTEM
INJECTION NOZZLE
The injection nozzle sprays pressurized fuel from the injection pump through the injection nozzle orifices
and into the combustion chamber.
4J series engines with the DFI (Double Formation Injection) Pintaux Type fuel injection nozzle having a sub-
injection hole is used. This injection nozzle contibutes to substantially minimize the diesel nocking sound
noticeable in the cold engine idling operation.

6C Ð 8 FUEL SYSTEM
FUEL FILTER CARTRIGE
DISASSEMBLY
·Drain fuel completely from the fuel filter.
·Protect the filter body with cloth and lightly grip with
a vise.
·Remove sedimentor center.
·Remove the cartridge using a filter wrench.
Filter wrench: 5-8840-0253-0(J-22700)
REASSEMBLY
·Install the sedimentor center.
Clean the cartridge mounting surface of filter body
so that the cartridge can be securely.
Apply engine oil thinly to new cartridge o-ring.
·To facilitate bleeding, fill the new cartridge with
light oil.
·Tighten the cartridge until o-ring comes in contact
with the sealing, taking care not to spill the light
oil.
·Retighten 1/3~2/3 using a filter wrench.
Filter wrench: 5-8840-0253-0(J-22700)
Bleeding
·Operate priming pump to send the air in the fuel
system to the injection pump.
·Loosen injection pump bleeding plug, and operate
the priming pump until no bubble is made.
·Tighten the bleeding plug.
·Start the engine, and if it is not started in 10 sec-
onds or less, repeat the bleeding steps.
·Make sure of no fuel leakage, and tighten the
priming pump.
Draining
·When the water in the sedimentor reaches the
specified volume, warning light is actuated.
In this case, follow the draining steps below.
·Set a vinyI hose over the drain plug.
·Loosen the drain plug.
·To drain the water, operate the priming pump
several times.
·After draining, tighten the drain plug.
·Operate the priming pump several times to check
for fuel leakage.
·Check and see the warning light is off.

FUEL SYSTEM 6C Ð 15
REMOVAL
Preparation:
·Disconnect battery ground cable.
·Drain coolant.
1. Air Cleaner Cover & Air Duct
2. Intercooler Assembly (4JG2-T ONLY)
· Refer to Intercooler Assembly removal.
3. Radiator Assembly
·Disconnect upper and lower hoses on the engine
side.
4. Cooling Fan Assembly
·Remove cooling fan asm and remove fan pulley
and spacer.
5. P/S Pump Drive Belt
·Loosen P/S pump lock bolt and adjust bolt remove
two drive belts.
6. AC Generator Drive Belt
·Loosen AC generator mounting bolt (under side)
and adjust, bolt and remove drive belt.
7. Timing Gear
·Refer to Timing Gear Removal
·Remove the loosened nut and fixing bolt and
remove the timing gear.
8.Fuel Filter Assembly
9. Injection Pump Harness
·Remove tachometer sensor, throttle sensor, and
fuel cut solenoid, harness.
10. Fuel Hose & CSD Hose
·Disconnect inlet hose and outlet hose and keep
hose end up to prevent fuel from coming out.
·Disconnect CSD hose.
11. Injection Pump Control Cable
12. Injection Pipe
·Release pipe clip.
·Remove the flare nut on the pump side.
·Remove the flare nut on the injection nozzle side,
and remove the injection pipe.
CAUTION
·Be sure to plug the injection nozzle holder and
delivery holder to prevent the entry of foreign
matter.
13. Injection Pump Assembly
·Remove pump mounting nut
·Loosen injection pump rear bracket adjuster lock
bolt.
·Remove the mounting bolt on the engine side, and
pull out the pump behind the engine.

6C Ð 16 FUEL SYSTEM
20 (2.0/15)N·m (Kg·m/lb·ft)
·Tighten the injection pump bracket bolts 8 to the
specified torque..
40 (4.1/30)N·m (Kg·m/lb·ft)
12. Injection Pipe
·Connect the pump side and nozzle side of the pipe,
and tighten securely.
·Install clip where it was.
11. Injection Pump Control Cable
·See adjustment of accelerator control cable.
10. Fuel Hose & CSD Hose
9. Injection Pump Harness
·Mount engine harness and connect it to switches.
8. Fuel Filter Assembly
7. Timing Gear
·Refer to Timing Gear in Section 6A2.
6. AC Generator Drive Belt
·Mount AC Generator drive belt and adjust belt
tension.
·See drive belt adjustment in section 6B.
5. P/S Pump Drive Belt
·Mount P/S pump drive belt and adjust belt tension.
·See drive belt adjustment in section 6B.
4. Cooling Fan Assembly
·Mount fan pulley, distance piece, and cooling fan
asm (in this order) on the water pump, and tighten
to the specified torque.
3. Radiator Assembly
2. Intercooler Assembly (4JG2-T ONLY)
·See installation of intercooler.
·Pour coolant.
·Connect battery ground cable.
1. Air Cleaner Cover & Air Duct
INSTALLATION
13. Injection Pump Assembly
·Tighten the injection pump bracket bolts 7 to the
specified torque..
8 (0.8/69)N·m (Kg·m/lb·in)

ENGINE ELECTRICAL 6D1 Ð 1
SECTION 6D
ENGINE ELECTRICAL
CONTENTS
Battery................................................................................................................................... Section 6D1
Starting System ................................................................................................................... Section 6D2
Charging System.................................................................................................................. Section 6D3
QOS-IIIPreheating System ................................................................................................. Section 6D6
SECTION 6D1
BATTERY
CONTENTS
General Description ......................................... 6D1Ð1
Diagnosis .......................................................... 6D1Ð1
On-Vehicle Service........................................... 6D1Ð3
Battery Charging .......................................... 6D1Ð3Jump Starting .............................................. 6D1Ð3
Removal and Installation of Battery .......... 6D1Ð4
GENERAL DESCRIPTION
There are six battery fluid caps at the top of the
battery. These are covered by a paper label.
The battery is completely sealed except for the six
small vent holes at the side. These vent holes per-
mit the escape of small amounts of gas generated
by the battery.
This type of battery has the following advantages
over conventional batteries:1. There is no need to add water during the entire
service life of the battery.
2. The battery protects itself against overcharging.
The battery will refuse to accept an excessive
charge.
(A conventional battery will accept an excessive
charge, resulting in gassing and loss of battery
fluid.)
3. The battery is much less vulnerable to self-
discharge than a conventional type battery.
DIAGNOSIS
1. VISUAL INSPECTION
Inspect the battery for obvious physical damage,
such as a cracked or broken case, which would
permit electrolyte loss.
Replace the battery if obvious physical damage is
discovered during inspection.
Check for any other physical damage and correct it
as necessary. If not, proceed to Step 2.
2. HYDROMETER CHECK
There is a built-in hydrometer (Charge test indica-
tor) at the top of the battery. It is designed to be
used during diagnostic procedures.Before trying to read the hydrometer, carefully
clean the upper battery surface.
If your work area is poorly lit, additional light may
be necessary to read the hydrometer.
a. BLUE RING OR DOT VISIBLE Ð Go to Step
4.
b. BLUE RING OR DOT NOT VISIBLE Ð Go to
Step 3.

6D1 Ð 2 ENGINE ELECTRICAL
3. FLUID LEVEL CHECK
The fluid level should be between the upper level
line and lower level line on side of the battery.
a. CORRECT FLUID LEVEL Ð Charge the bat-
tery.
b. BELOW LOWER LEVEL Ð Replace battery.
4. VOLTAGE CHECK
(1) Put voltmeter test leads to battery terminals.
a. VOLTAGE IS 12.4V OR ABOVE Ð Go to
Step 5.
b. VOLTAGE IS UNDER 12.4V Ð Go to proce-
dure (2) below.
(2) Determine fast charge amperage from specifi-
cation. (See Main Data and Specifications in
this section).
Fast charge battery for 30 minutes at amperage
rate no higher than specified value.
Take voltage and amperage readings after
charge.
a. VOLTAGE IS ABOVE 16V AT BELOW 1/3 OF
AMPERAGE RATE Ð Replace battery.
b. VOLTAGE IS ABOVE 16V AT ABOVE 1/3 OF
AMPERAGE RATE Ð Drop charging voltage
to 15V and charge for 10 - 15 hours.
Then go to Step 5.
c. VOLTAGE IS BETWEEN 12V AND 16V Ð
Continue charging at the same rate for an
additional 3-1/2 hours. Then go to Step 5.
d. VOLTAGE IS BELOW 12V Ð Replace battery.
5. LOAD TEST
(1) Connect a voltmeter and a battery load tester
across the battery terminals.
(2) Apply 300 ampere load for 15 seconds to
remove surface charge from the battery.
Remove load.
(3) Wait 15 seconds to let battery recover. Then
apply specified load from specifications (See
Main Data and Specifications in this section).
Read voltage after 15 seconds, then remove
load.
a. VOLTAGE DOES NOT DROP BELOW THE
MINIMUM LISTED IS FOLLOWING TABLE Ð
The battery is good and should be returned
to service.
b. VOLTAGE IS LESS THAN MINIMUM
LISTED Ð Replace battery.
ESTIMATED
MINIMUM
TEMPERATURE
VOLTAGE
¡F ¡C
70 21 9.6
60 16 9.5
50 10 9.4
40 4 9.3
30 Ð1 9.1
20 Ð7 8.9
10 Ð12 8.7
0 Ð18 8.5
The battery temperature must be estimated by feel and by the
temperature the battery has been exposed to for the
preceding few hours.

ENGINE ELECTRICAL 6D1 Ð 3
BATTERY CHARGING
Observe the following safety precautions when
charging the battery:
1. Never attempt to charge the battery when the
fluid level is below the lower level line on the
side of the battery. In this case, the battery
must be replaced.
2. Pay close attention to the battery during the
charging procedure.
Battery charging should be discontinued or the
rate of charge reduced if the battery feels hot to
the touch.
Battery charging should be discontinued or the
rate of charge reduced if the battery begins to
gas or spew electrolyte from the vent holes.
3. In order to more easily view the hydrometer
blue dot or ring, it may be necessary to jiggle or
tilt the battery.
4. Battery temperature can have a great effect on
battery charging capacity.
5. The sealed battery used on this vehicle may be
either quick-charged or slow-charged in the
same manner as other batteries.
Whichever method you decide to use, be sure
that you completely charge the battery. Never
partially charge the battery.
JUMP STARTING
JUMP STARTING WITH AN AUXILIARY
(BOOSTER) BATTERY
CAUTION:
Never push or tow the vehicle in an attempt to
start it. Serious damage to the emission system
as well as other vehicle parts will result.
Treat both the discharged battery and the
booster battery with great care when using
jumper cables. Carefully follow the jump
starting procedure, being careful at all times to
avoid sparking.
WARNING:
Failure to carefully follow the jump starting
procedure could result in the following:
1. Serious personal injury, particulaly to
your eyes.
2. Property damage from a battery explo-
sion, battery acid, or an electrical fire.
3. Damage to the electronic components of
one or both vehicles particularly. Never expose the battery to an open flame or elec-
trical spark. Gas generated by the battery may catch
fire or explode.
Remove any rings, watches, or other jewelry before
working around the battery. Protect your eyes by
wearing an approved set of goggles.
Never allow battery fluid to come in contact with
your eyes or skin.
Never allow battery fluid to come in contact with
fabrics or painted surfaces.
Battery fluid is a highly corrosive acid.
Should battery fluid come in contact with your
eyes, skin, fabric, or a painted surface, immediately
and thoroughly rinse the affected area with clean
tap water.
Never allow metal tools or jumper cables to come
in contact with the positive battery terminal, or any
other metal surface of the vehicle. This will protect
against a short circuit.
Always keep batteries out of the reach of young
children.
JUMP STARTING PROCEDURE
1. Set the vehicle parking brake.
If the vehicle is equipped with an automatic
transmission, place the selector lever in the
ÒPARKÓ position.
If the vehicle is equipped with a manual trans-
mission place the shift lever in the ÒNEUTRALÓ
position.
Turn ÒOFFÓ the ignition.
Turn ÒOFFÓ all lights and any other accessory
requiring electrical power.
2. Look at the built-in hydrometer.
If the indication area of the built-in hydrometer
is completely clear, do not try to jump start.
3. Attach the end of one jumper cable to the posi-
tive terminal of the booster battery.
Attach the other end of the same cable to the
positive terminal of the discharged battery.
Do not allow the vehicles to touch each other.
This will cause a ground connection, effectively
neutralizing the charging procedure.
Be sure that the booster battery has a 12 volt
rating.
4. Attach one end of the remaining cable to the
negative terminal of the booster battery.
Attach the other end of the same cable to a
solid engine ground (such as the A/C com-
pressor bracket or the generator mounting
bracket) of the vehicle with the discharged bat-
tery.
This ground connection must be at least 450
mm (18 in) from the battery of the vehicle
whose battery is being charged.
ON-VEHICLE SERVICE

6D1 Ð 4 ENGINE ELECTRICAL
WARNING:
Never attach the end of the jumper cable
directly to the negative terminal of the dead
battery.
5. Start the engine of the vehicle with the good
battery.
Make sure that all unnecessary electrical acces-
sories have been turned ÒOFFÓ.
6. Start the engine of the vehicle with the dead
battery.
7. To remove the jumper cables, follow the above
directions in the reverse order.
Be sure to first disconnect the negative cable
from the vehicle with the discharged battery.
REMOVAL AND INSTALLATION OF THE
BATTERY
REMOVAL
1. Negative cable
2. Positive cable
3. Retainer screw and rods
4. Retainer
5. Battery
INSTALLATION
To install the battery, follow the removal procedure
in the reverse order, noting the following points:
1. Make sure that the rod is hooked on the body
side.

STARTING SYSTEM 6D2 Ð 1
SECTION 6D2
STARTING SYSTEM
CONTENTS
PAGE
General Description .................................................................................................................. 6D2- 1
On-Vehicle Service .................................................................................................................... 6D2- 3
Unit Repair ................................................................................................................................. 6D2- 5
GENERAL DESCRIPTION
STARTING CIRCUIT
The cranking system consists of a battery, starter, starter switch, starter relay, etc. and these main compo-
nents are connected as shown in Figure. For details of the starting circuit.
STARTER
The starting system employs a magnetic type
reduction starter in which the motor shaft is also
used as a pinion shaft. When the starter switch is
turned on, the contacts of magnetic switch are
closed, and the armature rotates. At the same time,
the plunger is attracted, and the pinion is pushed
forward by the shift lever to mesh with ring gear.
Then, the ring gear runs to start the engine. When
the engine starts and the starter switch is turned off,