Fuel Tank: Description and Operation
Fuel Tank Insulators:
FUEL TANK
The fuel tank is located under the rear of the vehicle and is the fuel reservoir. The tank has a vertical baffle installed to support the filler tube and to serve as a slosh baffle. The fuel pump and fuel level sending unit assembly are mounted in the fuel tank as one assembly. The fuel tank assembly also consists of the fuel filler neck and filler cap. The fuel tank is make of steel and is coated internally with a special corrosion inhibitor.
FUEL FILLER NECK
To help prevent refueling with leaded fuel, the fuel filler neck has a built-in restrictor and deflector. The opening of the restrictor will accept only the smaller unleaded gasoline nozzle which must be fully inserted to bypass the deflector. Attempted refueling with a leaded fuel nozzle will result in fuel splashing back out of the filler neck.
Fuel Filler Cap:
FUEL TANK FILLER CAP
The fuel tank filler neck is equipped with a screw type cap. The threaded part of the cap requires several turns counterclockwise to remove. The long threaded area was designed to allow any remaining fuel tank pressure to escape during the cap removal operation. A ratchet type torque limiting device prevents over-tightening. 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.
NOTE: If a fuel filler cap requires replacement, only a cap with the same features should be used. Failure to use the correct cap can result in a serious malfunction of the system.
Vehicle Fuel Pipes:
Fuel Vapor Pipes:
NYLON FUEL AND VAPOR PIPES
Nylon fuel pipes are designed to perform the same job as the steel or flexible 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" ID for the fuel feed, and 5/16" ID for the fuel return.
The fuel feed and return pips are assembled as a harness. Retaining clips hold the pipes together and provide a means for attaching the pipes to the vehicle. Sections of the pipes that are exposed to chafing, high temperature or vibration are protected with heat resistant rubber hose and/or corrugated plastic conduit.
Nylon fuel pipes are somewhat flexible and can be formed around gradual turns under the vehicle. 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 more likely to kink if bent too far. Special care should be taken when working on a vehicle with nylon fuel pipes.
CAUTION: To reduce the risk of fire and personal injury:
^ Always cover nylon fuel lines with a wet towel before using a torch near them. Also, never expose the vehicle to temperatures higher than 115C (239F) for more than one hour, or more than 90C (194F) for any extended period.
^ Take care not to nick or scratch the nylon fuel lines. If damaged, they must be replaced.
The fuel feed and return pipes extend from the fuel pump/gauge sending unit to the engine compartment. The pipes are secured to the underbody with clip and screw assemblies. Both fuel feed pipes and return pipe must be properly routed and retained, and should be inspected occasionally for leaks, kinks, or dents. Check the fuel strainer on the fuel pump/fuel gauge assembly for damage or omission.
The vapor pipe extends from the fuel pump/gauge assembly to the canister. However, it does not follow the same route as the fuel feed pipe.
Due to the fact that the fuel pipes/hoses are under high pressure on fuel injected systems these systems require special consideration for service.
FUEL LINE "O" RINGS
Fuel feed and return pipe connections at the fuel metering system are sealed with replaceable O-ring seals. These O-ring seals are made of special material, and should only be serviced with the correct service part.