2004 ISUZU TF SERIES 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.

FUEL SYSTEM 6C – 9
FUEL TANK
Fuel Tank and Associated Parts


RTW46CLF000401

Legend

1. Bolt; Fuel Tank
2. Fuel Tank Band

3. Fuel Tube/Quick Connector

4. Fuel Filler Hose

5. Fuel Tank
6. Under Shield Band
7. Under Shield (only, specified model)
8. Evapo Pipe (only specified model)

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 – 11
5. Install the filler neck to the body with bolt.
6. Install the inner liner of the wheel house at rear left side.
7. Remove lifter from the fuel tank.
8.
Lower the vehicle.
9.
Tigten the filler cap until at least three clicks.
10.
Connect the battery ground cable.

6C – 12 FUEL SYSTEM
FUEL GAUGE UNIT
Fuel Gauge Unit and Associated Parts


RTW46CLF000501

Legend

1. Fuel Feed Port
2. Fuel Return Port

3. Fuel Emission Port

4. Fuel Gauge Unit and Sender Assembly

5. Connector; Fuel Gauge Unit


6. Fuel Tube/Quick Connector
7. Retainer Ring (Fuel Gauge Unit Lock)
8. Seal; Fuel Gauge Unit
9. Fuel Tank Assembly
10. Evapo Tube/Quick Connector

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.

6C – 14 FUEL SYSTEM

8.
Check leak.
Methed of leak check.

(1)
Plug end of quick connector and breather hose (Pull of
f
the breather hose from fuel tank) and tighten fuel fille
r
cap until at least one click are heard.
(2)
Apply water soap around the fuel gauge unit seal area.
(3)
Pressure air into the fuel tank from end of breather pipe
at 5psi (34.3 kPa/2.8kgf/cm
2) over 15 seconds.
(4)
Verify no bubbles around the fuel gauge unit seal area.
9.
Install the fuel tank assembly (9).
NOTE: Refer to “Install the fuel tank” in this section.