Isuzu engine 4j series. Service manual - part 65

6C - 4  ENGINE FUEL

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.

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ENGINE FUEL  6C - 5

FUEL FILTER AND WATER SEPARATOR

A cartridge type fuel filter and a water separator are
used along with the VE type injection pump.
As the inside of the injection pump is lubricated by the
fuel which it is pumping, the fuel must be perfectly
clean.  The fuel filter and the water separator remove
water particles and other foreign material from the fuel
before it reaches the injection pump.

The water separator has an internal float.  When the
float reaches the specified level, a warning light
comes on to remind you to drain the water from the
water separator.
A diaphragm type priming pump is installed at the top
of the water separator.  It is used during the water
draining and the air bleeding procedures.

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6C - 6  ENGINE FUEL

INJECTION NOZZLE

For 4J Series diesel engines, there are two types
available: Direct injection engine (4JB1/4JB1T) and
Indirect injection engine (4JG2). Accordingly, the
injection nozzles to be used are different depending on
the type of the engine and the combustion chamber.
The injection nozzle sprays pressurized fuel from the
injection pump into the combustion chamber through
the injection nozzle orifices.
4JB1 engines employ a hole type nozzle with four
injection orifices. The nozzle is made up of the nozzle
body and the needle valve assembly.
Pressurized fuel from the injection pump is sprayed by
the injection nozzle into the combustion chamber
through the nozzle body orifices.

4JB1-TC Engine
The two-spring nozzle holder has been developed to
reduce NOx (Nitrogen Oxides) and particulates from
direct injection diesel engine exhaust.

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ENGINE FUEL  6C - 7

ON-VEHICLE SERVICE

FUEL FILTER ASSEMBLY

REMOVAL

Preparation

•

Disconnect battery ground cable.

1. Fuel Filler Cap

2. Fuel Hose

•

Disconnect fuel hose from filter body.
Plug the hose ends to prevent fuel spillage.

3. Fuel Filter Assembly

•

Remove the fixing bolts on fuel filter bracket.

INSTALLATION

3. Fuel Filter Assembly

•

Install the fuel filter bracket then tighten fixing bolt.

2. Fuel Hose

•

Connect hoses to filter body.

1. Fuel Filler Cap

•

Connect the battery ground cable.

•

Feed fuel to the injection pump by means of the
priming, and bleed the fuel system.

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