ISUZU TROOPER 1998 Service Repair Manual

6B – 8 ENGINE COOLING
INSTALLATION
1. Thermostat
1) The jiggle valve of the thermostat must face the
cylinder head side.
2. Gasket
3. Install thermostat housing and tighten bolt to the
specified torque.
Torque: 20 N·m (2.0 kg·m/14.5 lb ft)
4. Reconnect water hose
1) Fill coolant to full level.
2) Reconnect battery ground cable.
5. Start the engine check for coolant leakage.

ENGINE COOLING 6B – 9
RADIATOR
REMOVAL
1. Disconnect battery ground cable
2. Loosen drain plug to drain coolant.
3. Radiator Hose
1) Disconnect lower hose and upper hose from the
engine.
4. Fan Guide
1) Remove clips on both sides and the bottom lock.
5. Reservoir Tank Hose
1) Disconnect the hose from radiator.
6. Bracket
7. Radiator Assembly
1) Remove the radiator assembly upward by the
hoses taking care not to damage the radiator
core by the fan blade.
2) Remove rubber cushions on both sides of the
bottom.
INSPECTION
Radiator Cap
1) Measure the valve opening pressure with the
radiator cap tester. Replace the radiator cap if it
exceeds the standard.
Valve opening pressure: 93.2 – 122.7 kPa
(0.95 – 1.25 kg/cm
2/
13.5 – 17.8 psi)
Check the condition of the negative pressure valve in
the center of the valve seat side of the cap. If the valve
seat does not move smoothly due to rust or dust, clean
and replace the radiator cap.Radiator Core
1) Deformed radiator fins could reduce radiation
effects, resulting in overheating. Straighten the fins.
In such a case, take care not to damage the fin
roots.
2) Remove dust and other foreign materials.
Flushing the Radiator
1) Wash the inside of radiator and the coolant
passage with water and a neutral detergent.
Remove all scales and rust.
110RW017
110RS006

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

6B – 12 ENGINE COOLING
Torque:
For A.C. Generator fixing bolt
40 N·m (4.1 kg·m/29.7 lb ft)
For Adjusting plate fixing bolt
24 N·m (2.4 kg·m/17.4 lb ft)
For Adjusting plate lock bolt
19 N·m (1.9 kg·m/13.7 lb ft)
2) Adjust the A/C compressor drive belt by tightening
the belt tensioner bolt.
Legend
(1) Crankshaft Pulley
(2) A.C. Generator Pulley
(3) Cooling Fan Pulley
(4) A/C Compressor Pulley
(5) Belt Tensioner Pulley
5
3
24
1
012RW110

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 – 2 ENGINE FUEL
FUEL FLOW
1
14 Except above region
89
10111
2
2
4
12
5 6
7
3
13
14 For Europe, Nicaragua,
Argentina, Philippin
11
4
Legend
(1) Fuel Filler Cap
(2) Fuel Tank
(3) Rollover Valve
(4) Fuel Supply Pipe
(5) Fuel Filter with Priming Pump
(6) Fuel Pump
(7) High Pressure Oil Pump(8) Cylinder Head
(9) Injector
(10) Orifice
(11) Fuel Return Pipe
(12) Fuel Tank Pressure Release Hose
(13) Intake Air Duct
(14) Fuel Tank Pressure Control Valve
040R200001

ENGINE FUEL 6C – 3
FUEL PUMP
1
2
3 4
Legend
(1) High Pressure Oil Pump
(2) To Injector(3) From Fuel Tank
(4) Fuel Pump
140RW041

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

ENGINE FUEL 6C – 5
FUEL FILTER
Legend
(1) Priming Pump
(2) Fuel Filter Cartridge
A cartridge type fuel filter is used along with the piston
type fuel pump on the high pressure oil pump.
The fuel filter removes foreign material from the fuel
before it reaches the fuel pump.
A diaphragm type priming pump is installed at the top of
the fuel filter. It is used during the air bleeding
procedures.
INJECTOR ASSEMBLY
Legend
(1) Oil Passage
(2) Fuel Passage
1. Construction of Fuel Injector
The fuel injector is comprised of the solenoid
section, hydraulic line, and fuel line. Fuel injection is
controlled by the continuity time signal and
continuity start timing signal sent by the ECM
(Electronic Control Module) to the solenoid.
2. Working of Fuel Injector
1) The ECM detects the working of the engine from
its input signals, such as engine speed
accelerator throttle opening, and engine coolant
temperature, sending the optimal signals to the
solenoid.
1
2
041RW017
1
2
055RW018