Fuel System Cleaning Procedure

WARNING: This procedure will NOT remove all fuel vapors. DO NOT attempt any repair on the fuel tank or filler neck where heat or flame is required, as an explosion resulting in personal injury could occur.

NOTE: If the fuel is contaminated, or if there is foreign material in the tank, the tank can usually be cleaned. If the tank is rusted internally, it should be replaced.

PROCEDURE:

1. Disconnect the negative battery cable.
2. Disconnect the engine harness at the DIS coil module.
3. Place a dry chemical (Class B) fire extinguisher near the work area.
4. Relieve the fuel system pressure, refer to FUEL SYSTEM PRESSURE RELIEF.
5. Drain the fuel tank, refer to FUEL TANK DRAINING.
6. Remove the fuel tank, refer to FUEL TANK REMOVAL AND FUEL LEVEL SENDING UNIT.
7. Remove the external fuel filter and inspect for contamination. If the filter is plugged, replace it.
8. Move the tank away from heat, flame or other source of ignition. Remove the fuel level sending unit and inspect the condition of the strainer. If the strainer is contaminated, install a new strainer when reassembled.
9. Complete draining the tank by rocking it and allowing the fuel to run out of the fuel pump/level sending unit tank opening.
10. Purge the fuel tank, refer to FUEL TANK PURGING.
11. Disconnect the fuel feed pipe at the in-line filter and use air pressure to clean the fuel line. Apply air pressure in the opposite direction the fuel normally flows through the line. Disconnect the return line and apply air pressure to clean.
12. Use low air pressure to clean pipes on the fuel level sender unit assembly.
13. Install a new filter strainer on the fuel level sending unit, if required.
14. Install the fuel level sending unit with a new O-ring gasket into the tank and install the fuel tank. Connect the fuel level sender harness to the body harness. The fuel level lender harness must be routed below the sender unit fuel pipes. Connect all fuel lines except the feed line at the engine. Install the fuel filter.

NOTE: Care should be taken not to fold over or twist the strainer when installing the fuel level sending unit as this will restrict the flow. Also, assure that the strainer does not block the float arm full travel.

15. Connect a hose to the fuel feed line at the engine, and insert the other end of the hose into an empty one gallon fuel can.
16. Connect the battery cable.
17. Put 2.3 liters (six gallons) of clean fuel into the fuel tank and apply 12 volts to terminal "G" of the ALDL to operate the fuel pump. Pump two quarts of fuel into the can. This will purge the fuel pump and the fuel lines.
18. Remove the hose and reconnect the fuel line to the engine. Connect the engine harness connector to the DIS ignition module.
19. START the engine.
20. Check all connections for leaks. Tighten all hose clamps.