Notice: Do not use fuels containing methanol in order to prevent damage and corrosion to the fuel system.
The fuel supply is stored in the fuel tank. An electric fuel pump, which is located in the fuel tank with the fuel level sensor sending unit, pumps fuel through an in-line fuel filter to the engine. The pump provides fuel at a pressure greater than is needed by the injectors. The fuel pressure regulator keeps fuel available to the injectors at a regulated pressure. The unused fuel is returned to the fuel tank by a separate line.
Fuel Tank
The fuel tank is used to store fuel for the vehicle. The tank is located in the rear of the vehicle and is held in place by two metal straps that are attached to the underbody. The fuel tank is made of steel and is coated internally with a special corrosion inhibitor. Due to the internal coating of the fuel tank, the fuel tank is not repairable.The fuel tank shape includes a reservoir in order to maintain a constant supply of fuel around the fuel pump strainer during low fuel conditions and aggressive vehicle maneuvers. A fuel tank filler pipe check-valve tube is attached to the fuel tank and extends from the fuel tank inlet to the reservoir. The fuel tank filler pipe check-valve is located inside the fuel tank filler pipe check-valve tube and prevents fuel from splashing back out of the fuel tank filler pipe during refueling.
Fuel Tank Filler Neck
To help prevent refueling with leaded fuel, the fuel filler neck (2) has a built in restrictor and deflector. The opening in the restrictor will accept only the smaller unleaded gasoline fuel nozzle which must be fully inserted to bypass the deflector.
Fuel Filler Cap
Notice: If a fuel tank filler pipe cap requires replacement, use only a fuel tank filler pipe cap with the same features. Failure to use the correct fuel tank filler pipe cap can result in a serious malfunction of the fuel system.
The fuel tank filler neck is equipped with a screw type cap. The threaded part of the cap requires several turns counter-clockwise in order for removal. A built in ratchet type torque limiting device prevents over tightening. In order to install, turn the cap clockwise until a clicking noise is heard. This signals that the correct torque has been reached and the cap is fully seated.
Modular Fuel Sender Assembly
The modular fuel sender assembly mounts in the top of the fuel tank and is spring loaded to the bottom. It is designed to:
| • | Provide optimum fuel level in the internal fuel reservoir during all fuel tank levels and driving conditions. |
| • | Improve the measuring accuracy of fuel tank level. |
| • | Filters coarse contaminates from the fuel |
| • | House fuel pump and helps prevent fuel pump noise. |
| • | Include a check valve to inhibit back flow of fuel from fuel system. |
The fuel sender (1) consists of the following major components:
| • | Fuel pump flex pipe (2). |
| • | Fuel strainer (3). |
| • | Level sensor (4). |
| • | Fuel sender cover (5). |
Fuel Pump
A high pressure gerotor fuel pump is mounted to the fuel sender inside the fuel tank. The fuel is pumped to the engine at a specified flow and pressure through the fuel pump. Excess fuel is returned to the fuel tank by a return pipe. The fuel pump delivers a constant flow of fuel to the engine even during low fuel conditions and aggressive vehicle maneuvers.
The electric fuel pump operation is controlled by the Powertrain Control Module (PCM) through a fuel pump relay. Refer to Fuel Pump Electrical Circuit Diagnosis or Fuel Pump Electrical Circuit Diagnosis
Fuel Pump Strainer
A woven plastic fuel pump strainer is attached to the lower end of the fuel pump in the fuel tank. The functions of the fuel pump strainer are to filter contaminants and to wick fuel.
The life of the fuel pump strainer is generally considered to be that of the fuel pump. The fuel pump strainer is self-cleaning and normally requires no maintenance. Fuel stoppage at this point indicates that the fuel tank contains an abnormal amount of sediment or water, in which case the tank should be thoroughly cleaned. Refer to Fuel System Cleaning
Fuel Level Sensor
The fuel sensor is attached to the modular fuel sender assembly. As the position of the float varies with the fuel level, the rheostat produces a variable resistance between the fuel gage and ground. The fuel gage converts this variable resistance into the fuel level reading display on the instrument panel.
In-Pipe Fuel Filter
A stainless steel in-line fuel filter is used in the fuel feed line ahead of the fuel injection system. The steel filter housing (1) is constructed to withstand maximum fuel system pressure, exposure to fuel additives, and changes in temperature. The filter element (2) is made of paper, and is designed to trap particles in the fuel that may damage the injection system. A quick-connect type fitting is used at one end and an "O" ring where the fuel pipe screws into the fuel filter body on the other end. There is no service interval for fuel filter replacement. Replacement is required only if the fuel filter becomes restricted.
Nylon Fuel Pipes
Caution: In order to Reduce the Risk of Fire and Personal Injury:
• If nylon fuel pipes are nicked, scratched or damaged during installation,
Do Not attempt to repair the sections of the nylon fuel pipes. Replace them. • When installing new fuel pipes, Do Not hammer directly on the
fuel harness body clips as it may damage the nylon pipes resulting in a possible
fuel leak. • Always cover nylon vapor pipes with a wet towel before using a
torch near them. Also, never expose the vehicle to temperatures higher than
115°C (239°F) for more than one hour, or more than 90°C (194°F)
for any extended period. • Before connecting fuel pipe fittings, always apply a few drops
of clean engine oil to the male pipe ends. This will ensure proper reconnection
and prevent a possible fuel leak. (During normal operation, the O-rings located
in the female connector will swell and may prevent proper reconnection if
not lubricated.)
Nylon fuel pipes are designed to perform the same job as the steel or rubber fuel lines that they replace. The nylon pipes are constructed to withstand the maximum fuel system pressure, exposure to fuel additives and changes in temperature. There are two sizes used: 3/8" ID for the fuel feed, and 5/16" ID for the fuel return and are used on the modular sender. The nylon fuel pipes are somewhat flexible and can be formed around gradual turns. However, if forced into sharp bends, the nylon pipes will kink and restrict the fuel flow. Also, once exposed to fuel, the nylon pipes may become stiffer and are more likely to kink if bent too far. Take special care when working on a vehicle with nylon pipes.
Quick-Connect Fittings
Quick-connect fittings provide a simplified means of installing and connecting fuel system components. The fittings consist of a unique female connector and a compatible male pipe end. O-rings, located inside the female connector, provide the fuel seal. Integral locking tabs or fingers hold the fittings together.
Fuel Pipe O-Rings
Fuel feed and return pipe threaded connections at the fuel rail and fuel filter are sealed with replaceable O-ring seals. These O-rings seals are made of special material, and should only be serviced with the correct service part.
EVAP Pipes
The EVAP pipes are made of nylon, steel, and quick connectors. The EVAP pipes, and hoses carry fuel vapors from the fuel tank to the charcoal canister. Under no conditions use copper or aluminum tubing to replace steel tubing. Those materials do not have satisfactory durability to withstand normal vehicle vibrations and corrosion.
Fuel Pump Speed Control Relay (VIN 1)
