Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 1703

ENGINE FUEL  6C-3

General Description

6C-4  ENGINE FUEL

*

*

*

*

Applicable to EVAP Emission Control System

** Not applicable to EVAP Emission Control System

ENGINE FUEL  6C-5

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.

6C-6  ENGINE FUEL

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.