engine ISUZU TF SERIES 2004 Workshop Manual

ENGINE COOLING 6B – 17
Inspection and Repair
Make the necessary adjustments, repairs, and part
replacements if excessive wear or damage is discovered
during inspection.


Radiator Cap
Measure the valve opening pressure of the pressurizing valve
with a radiator filler cap tester.
Replace the cap if the valve opening pressure is outside the
standard range.
Valve opening pressure kPa (psi) 93.3





122.7 (13.5





17.8)
Cap tester: 5–8840–0277–0
Adapter: 5–8840–2603–0
Check the condition of the vacuum valve in the center of the
valve seat side of the cap. If considerable rust or dirt is found,
or if the valve seat cannot be moved by hand, clean or replace
the cap.





110RS006

Valve opening vacuum kPa (psi) 1.96




4.91 (0.28




0.71)


Radiator Core
1. A bent fin may result in reduced ventilation and overheating
may occur. All bent fins must be straightened. Pay close
attention to the base of the fin when it is being straightened.
2. Remove all dust, bugs and other foreign material.

Flushing the Radiator
Thoroughly wash the inside of the radiator and the engine
coolant passages with cold water and mild detergent. Remove
all signs of scale and rust.

Cooling System Leakage Check
Use a radiator cap tester to force air into the radiator through
the filler neck at the specified pressure of 196 kPa (28.5 psi)
with a cap tester:
 Leakage from the radiator
 Leakage from the coolant pump
 Leakage from the water hoses

6B – 18 ENGINE COOLING




110RS005

 Check the rubber hoses for swelling.

Installation
1. Install radiator assembly (9) with hose, taking care not to
damage the radiator core with a fan blade.
2. Support the radiator upper tank with the bracket (5) and
secure the radiator.
3. Connect reserve tank hose (6).
4. Install lower fan guide (3).
5. Connect radiator inlet hose and outlet hose (1) to the
engine.





RTW36BMH000101

6. Connect oil cooler hose to automatic transmission.
7. Connect battery ground cable.

ENGINE COOLING 6B – 19




RTW36BSH000101

8. Pour engine coolant up to filler neck of radiator, and up to
MAX mark of reserve tank.

Important operation (in case of 100% engine coolant
change) procedure for filling with engine coolant.


Engine coolant change
Refer to 6B-8 (Draining and Refilling Cooling System).

6B – 20 ENGINE COOLING
FAN CLUTCH WITH COOLING FAN
INSPECTION AND REPAIR
Make necessary correction or parts replacement if wear, damage or any other abnormal condition are found through
inspection.


033R300001
Visually inspect for damage, leak (sillicon grease) or other
abnormal conditions.
1. Inspection (on-vehicle)
1) Turn the fan clutch by hand when in a low temperature
condition before starting the engine, and confirm that it
can be turned readily.
2) Start the engine to warm it up until the temperature at
the fan clutch portion gets to around 80
C. Then stop
the engine and confirm that the fan clutch can be
turned with considerable effort (clutch torque) when
turned by hand.
If the fan clutch rotates more readily, however, this
indicates that the silicone grease is leaking internally.
Replace the fan clutch with a new one.



033RY00011
2. Inspection (in unit)
Warm up the bimetal of the fan clutch by using the heat
gun until the temperature gets to about 80
C when
measured with the thermistor. Then confirm that the fan
clutch can be turned with considerable effort (clutch
torque).
If the fan clutch retates more readily at this time, this
indicates that the silicone grease is leaking internally.
Replace the fan clutch with a new one.

FUEL SYSTEM 6C – 3

MAIN DATA AND SPECIFICATIONS
Description Item
4JA1T (L) 4JA1TC 4JH1TC
Injection pump type
Bosch distributor
VE type Bosch distributor VP44 type
Governor type Mechanical variable
(Half speed oil
pressure) Electrical controled
Timer type Oil pressure Electrical controled
Fuel feed pump type Vane with input shaft
Injection nozzle type Hole type
Number of injection nozzle orifices 5
Injection nozzle orifices
Inside diameter mm (in) 0.19 (0.0075) 0.17 (0.0067) 0.21 (0.0083)
19.1 (195) 19.0 (194) 19.5 (199) Injection nozzle designed operating
pressure MPa (kg/cm2) 1st
2nd 25.0 (255) 33.5 (328) 33.8 (331)
Main fuel filter type Disposable cartridge paper element


Precautions
When working on the fuel system, there are several things
to keep in mind:

Any time the fuel system is being worked on,
disconnect the negative battery cable except fo
r
those tests where battery voltage is required.

Always keep a dry chemical (Class B) fire
extinguisher near the work area.
 Replace all pipes with the same pipe and fittings that
were removed.
 Clean and inspect “O" rings. Replace if required.
 Always relieve the line pressure before servicing any
fuel system components.
 Do not attempt repairs on the fuel system until you
have read the instructions and checked the pictures
relating to that repair.
 Adhere to all Notices and Cautions.

NOTE:
Injection nozzle adjustment is possible only on the 4JA1L
engine.

6C – 4 FUEL SYSTEM
GENERAL DESCRIPTION
FUEL FLOW


RTW46CM F000201


The fuel system consists of the fuel tank, the fuel filter, the water separator, the injection pump, and the injection
nozzle.
The fuel from the fuel tank passes through the water separator and the fuel filter where water particles and other
foreign material are removed from the fuel.
Fuel, fed by the injection pump plunger, is delivered to the injection nozzle in the measured volume at the optimum
timing for efficient engine operation.
NOTE:
1 If it find abnormal condition on the fuel injector, refer to section 6E ENGINE DRIVEABILITY AND
EMISSIONS.
2 Do not contain "Additive for water drain" with fuel.

FUEL SYSTEM 6C – 7
INJECTION PUMP


RTW46CLF000201

4JA1T(L):
A Bosch Distributor Type Injection Pump is used. A single reciprocating/revolving plunger delivers the fuel uniformly
to the injection nozzles, regardless of the number of cylinders.
The governor, the injection timer, and the feed pump are all contained in the injection pump housing. The injection
pump is compact, light weight, and provides reliable high-speed operation.
The vacuum-type fast idle actuator increases the engine idling speed to provide the additional power required to
operate the air conditioner.
Fast idler diaphragm movement is caused by changes in the negative pressure created by the engine’s vacuum
pump.
The diaphragm motion is transferred to the injection pump control lever to increase or decrease the idling speed.

4JA1TC/4JH1TC:
The Bosch VP44 injection pump is electronically controlled. The pump controller combine to injection pump.
Signals from the pump controller are sent to the engine control module (ECM). In response to these signals, the
ECM selects the optimum fuel injection timing and volume for the existing driving conditions.

6C – 8 FUEL SYSTEM
INJECTION NOZZLE (4JA1L)

RTW46CM F000301
NOTE:


Injection nozzle adjustment is possible only on the 4JA1L engine.

A hole (with 5 orifices) type injection nozzle. It consists of the nozzle body and the needle valve assembly.
The injection nozzle assembly sprays pressurized fuel from the injection pump into the combustion chamber through
the nozzle body injection orifice.

6C – 10 FUEL SYSTEM
Removal
CAUTION: When repair to the fuel system has been
completed, start engine and check the fuel system for
loose connection or leakage. For the fuel system
diagnosis, see Section “Driveability and Emission".
1. Disconnect battery ground cable.
2. Loosen slowly the fuel filler cap.
NOTE: Be careful not to spouting out fuel because of change
the pressure in the fuel tank.
NOTE: Cover opening of the filler neck to prevent any dus
t
entering.
3. Jack up the vehicle.
4. Support underneath of the fuel tank with a lifter.
5. Remove the inner liner of the wheel house at rear left side.
6. Remove fixing bolt of the filler neck from the body.
7.
Disconnect the quick connector (3) of the fuel tube from the
fuel pipe.
NOTE: Cover the quick connector to prevent any dust entering
and fuel leakage.
NOTE: Refer to“Fuel Tube/Quick Connector Fittings” in this
section when performing any repairs.
8. Remove fixing bolt (1) of the tank band and remove the
tank band (2).
9.
Disconnect the pump and sender connector on the fuel
pump and remove the harness from weld clip on the fuel
tank.
10.
Lower the fuel tank (5).
NOTE: When lower the fuel tank from the vehicle, don’t scratch
each hose and tube by around other parts.













Installation
1. Raise the fuel tank.
NOTE: When raise the fuel tank to the vehicle, don’t scratch
each hose and tube by around other parts.
2. Connect the pump and sender connector to the fuel pump
and install the harness to weld clip on the tank.
NOTE: The connector must be certainly connected agains
t
stopper.
3. Install the tank band and fasten bolt.
Torque N·m (kg·m / lb ft)
68 (6.9 / 50)
NOTE: The anchor of the tank band must be certainly installed
to guide hole on frame.
4. Connect the quick connector of the fuel tube to the fuel pipe
and the evapo tube from evapo joint connector.
NOTE: Pull off the left checker on the fuel pipe.
NOTE: Refer to “Fuel Tube/Quick Connector Fittings” in this
section when performing any repairs.

FUEL SYSTEM 6C – 13

Removal
CAUTION: When repair to the fuel system has been
completed, start engine and check the fuel system for
loose connection or leakage. For the fuel system
diagnosis, see Section “Driveability and Emission".
1. Remove fuel tank assembly (9). Refer to “Fuel Tank
Removal" in this section.
2. Disconnect the quick connector (6) of the fuel tube from fuel
gauge unit.
3. Disconnect the quick connector (10) of the evapo tube from
fuel gauge unit.


140R100035

3. Remove the retainer ring (7) from the fuel tank with the
removal tool 5-8840-2602-0.
4.
Remove slowly the fuel gauge unit (4) from the fuel tank as
no bend float arm.
NOTE: Cover opening for the fuel gauge unit on fuel tank to
prevent any dust entering.
5.
Discard fuel gauge unit seal (8) because it cannot be
reusable.


Installation
1. Clean the seal surface of the fuel tank and the fuel gauge
unit.
NOTE: If there is dust on the seal surface, it becomes cause o
f
fuel leak.
2. Install the new fuel gauge unit seal (8) to opening of the fuel
tank as along the groove.
3. Install slowly the fuel gauge unit (4) into the fuel tank as no
bend float arm.
4.
Set flange of the fuel gauge unit on fuel gauge unit seal as
mating convexity of the fuel gauge unit and reentrant of the
fuel tank.
5.
Lock slowly the retainer ring (7) to the fuel tank with the
remover tool 5-8840-2602-0.
6. Connect the quick connector (10) of the evapo tube from
fuel gauge unit.
7.
Connect the quick connector (6) of the fuel tube to to gauge
unit.
NOTE: Pull off the left ckecker of the fuel pipe.
NOTE: Refer to “Fuel Tube/Quick Connector Fittings” in this
section when performing any repairs.