1998 ISUZU TROOPER check engine

6B – 10 ENGINE COOLING
Checking for Coolant Leakage
1) Check the cooling system for leakage with the
radiator cap tester by applying 196.0 kPa (28.4 psi)
air pressure from filler neck to inside the radiator.
INSTALLATION
1. Radiator Assembly
1) Install rubber cushions on both sides of radiator
bottom.
2) Install radiator assembly with hose, taking care
not to damage the radiator core by a fan blade.
2. Bracket
1) Support the radiator upper tank with the bracket
and fix the radiator.
3. Reserve Tank Hose
4. Fan Guide, Lower
5. Radiator Hose
1) Connect inlet hose and outlet hose to the
engine.
2) Connect battery ground cable.
3) Pour coolant up to filler neck of radiator, and up
to MAX mark of reserve tank.
4) Start engine to warm up, and check for coolant
level. Replenish coolant if it does not reach the
radiator filler neck, and tighten the cap
completely.
110RS005
012RW080

ENGINE COOLING 6B – 11
DRIVE BELT ADJUSTMENT
INSPECTION
Check drive belts for wear or damage, and replace with
new ones as necessary. Check belts for tension, and
adjust as necessary.
1) Check drive belt tension.
2) Push the middle of belt with a force of 98 N
(10 kg/22 lb) and check each belt for deflection.
Standard deflection:
For A.C. generator & fan pulley drive belt
Initial tension : 8 – 12 mm (0.31 – 0.47 in)
Tension at readjustment : Same as above.
For A/C compressor drive belt
Initial tension : 7 – 10 mm (0.28 – 0.38 in)
Tension at readjustment : 5 – 8 mm (0.20 – 0.31 in)
TENSION ADJUSTMENT
1) Loosen AC generator mounting bolt to move AC
generator, adjust belt tension and tighten to the
specified torque.
Legend
(1) Crankshaft Pulley
(2) A.C. Generator Pulley
(3) Cooling Fan Pulley
5
3
1 2 4
Legend
(1) Crankshaft Pulley
(2) A.C. Generator
(3) Cooling Fan Pulley
(4) A/C Compressor
(5) Belt Tensioner Pulley
012RW085
3
2
1
012RW084

ENGINE FUEL 6C – 1
ENGINE FUEL
CONTENTS
GENERAL DESCRIPTION
General Description . . . . . . . . . . . . . . . . . . 6C–1
On-Vehicle Service . . . . . . . . . . . . . . . . . . 6C–7
Fuel Filter Assembly . . . . . . . . . . . . . . . . 6C–7
Fuel Filter Cartridge . . . . . . . . . . . . . . . . 6C–7
Injector . . . . . . . . . . . . . . . . . . . . . . . . . . 6C–9
Fuel Pump Pipe . . . . . . . . . . . . . . . . . . . 6C–13High Pressure Oil Pump . . . . . . . . . . . . . 6C–15
Fuel Tank . . . . . . . . . . . . . . . . . . . . . . . . 6C–20
Fuel Gauge Unit . . . . . . . . . . . . . . . . . . . 6C–21
Fuel Filler Cap . . . . . . . . . . . . . . . . . . . . 6C–21
To realize the compatibility between low exhaust
emission and high engine output, an HEUI
(Hydraulically actuated Electronically controlled Unit
Injector) system, has been introduced. This system is
comprised of a hydraulic system, fuel system, and
electronic control system, using a high-pressure oil
pump in place of the conventional fuel injection pump.
The oil pressurized by means of this pump and by
signals from the ECM (Electronic Control Module)
actuates the fuel injector provided for each cylinder.
Inside of the fuel injector, fuel pressure is increased due
to the high-pressure oil. The ECM detects the driving
state of the vehicle, forms, signals sent by engine and
other part sensors, which determines the optimum fuel
injection amount and timing, thus controlling the fuel
injectors. Thus high engine output, good fuel economy,
and low exhaust emission are realized.When working on the fuel system, there are several
things to keep in mind:
1) Any time the fuel system is being worked on,
disconnect the negative battery cable except for
those tests where battery voltage is required.
2) Always keep a dry chemical (Class B) fire
extinguisher near the work area.
3) Replace all pipes with the same pipe and fittings
that were removed.
Clean and inspect “O” rings. Replace where
required.
4) Always relieve the line pressure before servicing
any fuel system components.
5) Do not attempt repairs on the fuel system until you
have read the instructions and checked the pictures
relating to that repair.
6) After maintenance work, push priming pump and
send enough fuel to the fuel system before starting
the engine.
NOTE: In comparison with the conventional engine,
the capacity of fuel passage in the 4JX1 engine is
larger. It takes the priming pump more time to fill the
engine with fuel.

6C – 4 ENGINE FUEL
HIGH PRESSURE OIL PUMP, OIL FLOW
1
33
32
31
30
1
2
3
4
56
8
97
10
11
12
13
14 23 29
25
28
27262415
16
17 18
19 20 21 22
Legend
(1) Camshaft
(2) Balance Shaft
(3) Crankshaft
(4) Oil Cooler and Oil Filter Assembly
(5) Oil Filter Relief Valve 98Kpa (1 kg/cm
2/14.2 Psi)
(6) Oil Cooler Relief Valve 245 Kpa (2.5 kg/cm2/
36 Psi)
(7) First Oil Pump
(8) Main Oil Relief Valve 588 Kpa (6 kg/cm
2/ 85 Psi)
(9) To Oil Pan
(10) To Oil Pan
(11) Injector
(12) Oil Rail
(13) Sub Oil Filter Relief Valve 98Kpa (1 kg/cm
2/
14.2 Psi)
(14) Sub Oil Filter
(15) Relief Valve 588 Kpa (6 kg/cm
2/ 85 Psi)
(16) Second Oil Pump(17) Oil Pan
(18) To Oil Pan
(19) Balance Shaft
(20) Cooling Jet Relief Valve 245 Kpa (2.5 kg/cm
2/
36 Psi)
(21) Cooling Jet
(22) To Oil Pan
(23) Two Way Check Valve
(24) Nipple Filter
(25) Edge Filter
(26) Edge Filter
(27) High Pressure Oil Pump Assembly
(28) To Oil Pan
(29) Pressure Control Valve
(30) To Oil Pan
(31) Turbocharger
(32) Oil Gallery
(33) Timing Gear Train
040RW018

6C – 14 ENGINE FUEL
NOTE:
1) Do not apply oil to the eye bolt.
2) Do not bend the fuel pump pipe.
5. Tifhten cap nut to specified torque.
Torque : 13 N·m (1.3 kg·m/113 lb ft)
NOTE: Do not apply oil to the cap nut.
6. Start the engine, check that the fuel leakage is not
found.

ENGINE FUEL 6C – 21
FUEL GAUGE UNIT
1
2
3
140R200033
REMOVAL
1. Disconnect battery ground cable.
2. Loosen fuel filler cap.
3. Drain fuel.
After drain the fuel tighten the drain plug with
specified torque.
Torque : 20 N·m (2.0 kg·m/14 lb ft)
4. Disconnect harness connector from fuel gauge unit.
5. Fuel Gauge Unit
1) Remove the fixing screws, then the fuel gauge
unit.
INSTALLATION
1. Fuel Gauge Unit
2. Connect the harness connector to the fuel gage
unit.
3. Fill the tank with fuel and tighten fuel filler cap.
4. Connect battery ground cable.
FUEL FILLER CAP
The fuel filler cap contains a vacuum valve. If a
negative pressure develops in the fuel tank, the
external valve of the fuel filler cap opens to allow the
fresh air to flow into the fuel tank through the vacuum
valve.
INSPECTION
Check the seal ring in the filler cap for presence of any
abnormality and for seal condition.
Replace the filler cap, if abnormal.Legend
(1) Vacuum Valve
(2) Pressure Valve
(3) Seal Ring Legend
(1) Fuel Tank Assembly
(2) Fuel Gauge Unit
(3) Drain Plug
1
3
2
060R200247

ENGINE ELECTRICAL 6D – 1
ENGINE ELECTRICAL
CONTENTS
Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6D–1
General Description . . . . . . . . . . . . . . . . 6D–1
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . 6D–1
On Vehicle Service . . . . . . . . . . . . . . . . . 6D–3
Main Data and Specification . . . . . . . . . . 6D–4
Starting System . . . . . . . . . . . . . . . . . . . . . 6D–5
General Description . . . . . . . . . . . . . . . . 6D–5
On Vehicle Service . . . . . . . . . . . . . . . . . 6D–7
Starter . . . . . . . . . . . . . . . . . . . . . . . . . . 6D–7
Unit Repair . . . . . . . . . . . . . . . . . . . . . . . 6D–8Charging System . . . . . . . . . . . . . . . . . . . . 6D–15
General Description . . . . . . . . . . . . . . . . 6D–15
Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . 6D–16
Unit Repair . . . . . . . . . . . . . . . . . . . . . . . 6D–17
Main Data and Specification . . . . . . . . . . 6D–22
QOS4 Preheating System . . . . . . . . . . . . . . 6D–23
General Description . . . . . . . . . . . . . . . . 6D–23
System Diagram . . . . . . . . . . . . . . . . . . . 6D–23
Inspection of QOS4 System Operation . . 6D–24
BATTERY
GENERAL DESCRIPTION
DIAGNOSIS
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 permit
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.
1. VISUAL INSPECTION (Step 1)
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 (Step 2)
There is a built-in hydrometer (Charge test indicator) 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 – Go to Step 4.
b. BLUE RING OR DOT NOT VISIBLE – Go to
Step 3.3. FLUID LEVEL CHECK (Step 3)
The fluid level should be between the upper level line
and lower level line on side of the battery.
a. CORRECT FLUID LEVEL – Charge the battery.
b. BELOW LOWER LEVEL – Replace battery.
4. VOLTAGE CHECK (Step 4)
(1) Put voltmeter test leads to battery terminals.
a. VOLTAGE IS 12.4V OR ABOVE – Go to Step 5.
b. VOLTAGE IS UNDER 12.4V – Go to procedure
(2) below.
(2) Determine fast charge amperage from
specification. (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 – Replace battery.

6D – 10 ENGINE ELECTRICAL
INSPECTION AND REPAIR
Repair or replace necessary parts if extreme wear or
damage is found during inspection.
Armature
1) Measure the outer diameter of commutator, and
replace with a new one if it is out of the limit.
Standard: 38.0 mm (1.50 in)
Limit: 36.5 mm (1.44 in)
2) Check for continuity between commutator and
segments. Replace commutator if there is no
continuity (i.e., disconnected).3) Check for continuity between commutator and
shaft. Also, check for continuity between
commutator and armature core, armature core and
shaft. Replace commutator if there is continuity
(i.e., internally grounded).
4) Measure runout of armature core and commutator
with a dial gage. Repair or replace, if it exceeds the
limit.
Armature
Standard: 0.05 mm (0.002 in) Max.
Limit: 0.1 mm (0.004 in)
Commutator
Standard: 0.05 mm (0.002 in) Max.
Limit: 0.1 mm (0.004 in)
065RW041
065RS015
065RS016
045RW045