Engine Fuel: Other Isuzu Axiom I

SERVICE PRECAUTION

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

1. Any time the fuel system is being worked on, disconnect the battery ground cable except for those tests where battery voltage is required.
2. Always keep a dry chemical (Class B) fire extinguisher near the work area.
3. Replace all pipes with the same pipe and fittings that were removed.
4. Clean and inspect "O" rings. Replace if required.
5. Always relieve the line pressure before servicing any fuel system components.
6. Do not attempt repairs on the fuel system until you have read the instructions and checked the pictures relating to that repair.
7. 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.

The vapor pressure sensor and vent solenoid valve for vapor pressure sensor are used to detect abnormalities in the evaporative emission control system.

The PCM decides whether there an abnormality in the evaporative emission control system based on vapor pressure sensor signal.

FUEL METERING

The Powertrain Control Module (PCM) 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 PCM.

With receipt of the signals sent from the MAP sensor, Intake Air Temperature sensor and others, the PCM determines an appropriate fuel injection pulse width feeding such information to the fuel injector valves to affect an appropriate air/fuel ratio.

The Multiport Fuel Injection system utilizes an injection system where the injectors turn on at every crankshaft revolution. The PCM 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.

Refer to BASIC DIAGNOSTIC PROCEDURES for more information and diagnosis.

IN-TANK FUEL FILTER

The filter is located on the lower end of fuel pickup tube in the fuel tank. The fuel filter prevents dirt and water the fuel system not unless the filter is submerged in water. The fuel filter is maintenance free, that requires no maintenance. Excess water and sediment in the tank restricts fuel supply to the engine, resulting in engine stall. If this happens, the fuel tank would need to be cleaned thoroughly.

Pressure Tests

For the pressure test to the fuel system, refer to FUEL SYSTEM .

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PRECAUTIONS

1. Do not light a match or create a flame.
2. Keep flames away from your work area to prevent flammable materials from catching fire.
3. Disconnect battery ground cable to prevent electrical shorts.
4. Pre-treat piping system or associated parts from thermal damage or from spattering when welding or similar heat generating work.

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Note. An O-ring inside the quick connector provides the seal between the quick connector and the port. Be careful not to damage the mating surfaces and O-ring when attaching the connector. Do not allow foreign material to enter the connector or the port.

Do not expose the assembly to battery electrolyte or do not wipe the assembly with a cloth used to wipe off spilt battery electrolyte.

Piping that has been splattered with battery electrolyte or battery electrolyte soaked cloth that was wiped on the piping cannot be used.

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1. Open the fuel cap to relieve the fuel pressure in the tank. Use compressed air to remove any dirt on the fuel quick connect fittings prior to disconnecting the fittings. When disconnecting the fuel pipe, cover the area with a cloth to prevent fuel from splashing as the fuel pipe may still have some pressure in it.
2. For removal of the quick connector, pull out the connector with the other hand while pressing the square relieve button of the connector, as illustrated.

Note. Do not use tools of any kind. Only use bare hands when disconnecting the connector. Use a lubricant (light oil) and/or push and pull the connector until the pipe is disconnected.

Cover the connectors that was removed with a plastic bag, to prevent dust or rain water from entering.

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REUSE OF QUICK-CONNECTOR

1. Replace the port and connector if scratch, dent or crack is found.
2. Remove any dirt build up on the port when installing the connector. Replace the connector, if there is any forms of rust, dent, scratch.
3. After cleaning the port, insert it straight into the connector until it clicks. After it clicks, try pulling it out to make sure that it is not drawn and is securely locked.

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