Isuzu engine C22NE / 22LE / 20LE. Manual - part 31

ENGINE FUEL  6C-3

General Description

Legend

1 Filter Cap
2 Fuel Tank
3 Rollover Valve *
4 Fuel Pump
5 Fuel Filter
6 Fuel Rail
7 Intake Manifold

8 Fuel Pressure Control Valve
9 Duty Solenoid Valve

10 Throttle Valve
11 Canister *
12 Check and Relief Valve *
13.Drain hose *
14.2 Way Valve **

This illustration is based on the with
canister model.

*

Applicable to EVAP Emission Control System

** Not applicable to EVAP Emission Control System

6C-4  ENGINE FUEL

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 for 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.

All gasoline engines are designed to use only unleaded
gasoline. Unleaded gasoline must be used for proper emission
control system operation.
Its use will also minimize spark plug fouling and extend engine
oil life. Using leaded gasoline can damage the emission control
system and could result in loss of emission warranty coverage.
All cars are equipped with an Evaporative Emission Control

System. The purpose of the system is to minimize the escape

of fuel vapors to the atmosphere.

Service Precaution

CAUTION:
Always use the correct fastener in the proper location.
When you replace a fastener, use ONLY the exact part
number for that application. ISUZU will call out those
fasteners that require a replacement after removal. ISUZU
will also call out the fasteners that require thread lockers
or thread sealant. UNLESS OTHERWISE SPECIFIED, do
not use supplemental coatings (Paints, greases, or other
corrosion inhibitors) on threaded fasteners or fastener
joint interfaces. Generally, such coatings adversely affect
the fastener torque and the joint clamping force, and may
damage the fastener. When you install fasteners, use the
correct tightening sequence and specifications. Following
these instructions can help you avoid damage to parts and
systems.

ENGINE FUEL  6C-5

Fuel Metering

Engine Control Module (ECM) is in complete control of this fuel
delivery system during normal driving conditions.
The intake manifold function, like that of a diesel, is used only
to let air into the engine. The fuel is injected by separate
injectors that are mounted over the intake manifold.
The Manifold Absolute Pressure (MAP) sensor measures the
changes in the intake manifold pressure which result from
engine load and speed changes, which the MAP sensor
converts to a voltage output.
This sensor generates the voltage to change corresponding to
the flow of the air drawn into the engine.
The changing voltage is transformed into an electric signal and
provided to the ECM.
With receipt of the signals sent from the MAP sensor, Intake
Air Temperature sensor and others, the ECM determines an
appropriate fuel injection pulse width feeding such information
to the fuel injector valves to effect an appropriate air/fuel ratio.
The Multiport Fuel Injection system utilizes an injection system
where the injectors turn on at every crankshaft revolution. The
ECM controls the injector on time so that the correct amount of
fuel is metered depending on driving conditions.
Two interchangeable "O" rings are used on the injector that
must be replaced when the injectors are removed.
The fuel rail is attached to the top of the intake manifold and
supplies fuel to all the injectors.
Fuel is recirculated through the rail continually while the engine
is running. This removes air and vapors from the fuel as well as
keeping the fuel cool during hot weather operation.
The fuel pressure control valve that is mounted on the fuel rail
maintains a pressure differential across the injectors under all
operating conditions. It is accomplished by controlling the
amount of fuel that is recirculated back to the fuel tank based
on engine demand.
See Section "Driveability and Emission" for more information
and diagnosis.

6C-6  ENGINE FUEL

Fuel Filter

Fuel Filter and Associated Parts

Legend

1 Fuel Hose
2 Fuel Filter

3 Fixing bolt

3

1

2

Removal

CAUTION: When repair to the fuel system has been
completed, start engine and check the fuel system for
loose connections or leakage. For the fuel system
diagnosis, see Section "Driveability and Emissions".
1. Disconnect battery ground cable.

2. Remove fuel filler cap.

3. Loosen the fixing bolt and disconnect fuel hoses (1).

4. Remove fuel filter (2).