Isuzu N-Series. Manual - part 608

6C-2 ENGINE FUEL

GENERAL DESCRIPTION

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

• Any time the fuel system is being worked on, dis-

connect the negative battery cable except for those
tests where battery voltage is required.

• Always keep a dry chemical (Class B) fire extin-

guisher near the work area.

• Replace all pipes with the same pipe and fittings

that were removed.
Clean and inspect O-rings. Replace where re-
quired.

• 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 pic-
tures relating to that repairs.

• The 4JH1-TC engine is equipped with the electron-

ically controlled fuel injection system.
For information on fuel injection pump mainte-
nance and/or part replacement, contact the Bosch
Automotive Systems Corporation.

• Contact the Bosch Automotive Systems Corpora-

tion for information on 4JH1-TC engine fuel injec-
tion nozzle maintenance.

ENGINE FUEL 6C-3

Fuel Flow

The fuel system consists of the fuel tank, the water separator, the fuel filter, the injection pump, and the injection noz-
zle.
The fuel from the fuel tank passes through the water separator and the fuel filter where water particles and other for-
eign 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.

Legend

1. CSD solenoid valve

5. Fuel filter

2. Nozzle

6. Water separator

3. Fuel cut solenoid valve

7. Fuel tank

4. VE type injection pump

N6A3392E

6C-4 ENGINE FUEL

Fuel Flow (4JH1-TC)

Legend

1. EDU

4. Fuel tank

2. Nozzle

5. Fuel filter

3. Injection pump

N6A3393E

ENGINE FUEL 6C-5

Injection Pump

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.
An aneroid compensator is available as an option for vehicles to be operated at high altitudes. It adjusts the fuel and
air mixing ratio.

Legend

A. From fuel filter

8. Plunger spring

B. To nozzle

9. Control sleeve

1. Governor spring

10. Delivery valve

2. Control lever

11. Plunger

3. Control lever shaft

12. Fuel cut solenoid valve

4. Drive shaft

13. Tension lever

5. Feed pump gear

14. Collector lever

6. Driver disc

15. Aneroid compensator

7. Timer

N6A3394E