For 1990-2009 cars

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

### Fuel Tank

The fuel tank (1) is used to store fuel for the vehicle. The tank is located in the rear of the vehicle and is held in place by three metal straps that are attached to the underbody. The fuel tank is made of high density polyethlene. 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 tube is attached to the fuel tank and extends from the fuel tank inlet to the reservoir.

### Fuel Tank Filler Pipe Cap

Notice: Use a fuel tank filler pipe cap with the same features as the original when a replacement is necessary. Failure to use the correct fuel tank filler pipe cap can result in a serious malfunction of the fuel system.

In order to prevent refueling with leaded fuel, the fuel tank filler pipe has a built-in restrictor and deflector.

The fuel tank filler pipe is equipped with a threaded-type fuel tank filler pipe cap. The threaded part of the fuel tank filler pipe cap requires several turns counterclockwise before it can be removed. A built-in torque-limiting device prevents over tightening of the fuel tank filler pipe cap. In order to install the fuel tank filler pipe cap, turn the fuel tank filler pipe cap clockwise until at least 3 clicking noises are heard. The clicking noises signal that the correct torque has been reached and that the fuel tank filler pipe 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 (2) to inhibit back flow of fuel from fuel system.

The fuel sender (1) consists of the following serviceable components:

• | Fuel strainer (3).

• | Level sensor (4).

### Fuel Pump

An electric fuel pump located in the modular sender assembly is used to provide fuel pressure. To control fuel pump operation, a fuel pump relay and fuel pump switch are used. When the ignition lock cylinder is turned to RUN position, the fuel pump relay activates the electric fuel pump for approximately two seconds to prime the injectors. If the PCM does not receive reference pulses after this time, the PCM opens the fuel pump relay ground circuit. The relay will reactivate the fuel pump when the PCM receives reference pulses.

### Fuel Pump Strainer

A woven plastic strainer is located on the lower end of the fuel sender. This filter prevents dirt from entering the fuel line and also stops water unless the filter becomes completely submerged in water. This filter 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. Therefore, should this occur, the fuel tank should be removed and thoroughly cleaned and the tank filter replaced.

### 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 fuel filter is used in the fuel feed pipe ahead of the fuel injection system. The fuel filter is mounted directly in front of the fuel tank. The fuel filter housing (1) is constructed of steel with a quick-connect fitting at the inlet of the fuel filter and a threaded fitting at the outlet of the fuel filter. The threaded fitting is sealed with an O-ring, which is replaceable. The filter element (2) is made of paper and is designed to trap particles suspended in the fuel that may damage the injection system.

There is no service interval for in-pipe fuel filter replacement. Only replace the in-pipe fuel filter if it is restricted.

### Fuel Feed and Fuel Return Pipes

The fuel feed and fuel return pipes carry fuel from the fuel sender assembly to the fuel injection system and back to the fuel sender assembly.

### 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 they replace. Nylon pipes are constructed to withstand maximum fuel system pressure, exposure to fuel additives and changes in temperature. There are two sizes used: 3/8 inches ID for the fuel feed, and 5/16 inches ID for the fuel return and are used on the modular sender. Nylon fuel pipes are somewhat flexible and can be formed around gradual turns. However, if forced into sharp bends, nylon pipes will kink and restrict fuel flow. Also, once exposed to fuel, nylon pipes may become stiffer and are more likely to kink if bent too far. Special care should be taken when working on a vehicle with nylon pipes.

### Quick Connect Fittings

Quick-connect type fittings provide a simplified means of installing and connecting fuel system components. Depending on the vehicle model, there are two types of quick-connect fittings, each used at different locations in the fuel system. Each type of quick-connect fitting consists of a unique female connector and a compatible male fuel pipe end. O-rings, located inside the female connector, provide the fuel seal. Integral locking tabs or fingers hold the quick-connect 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.