Fuel System Cleaning Procedure

WARNING: This procedure will not remove all fuel vapors. Do not attempt any repair on the tank or filler neck where heat or flame is required, as an explosion resulting in personal injury could occur. Have a Class B fire extinguisher near the work area.

NOTE: If the trouble is due to contaminated fuel or foreign material that has been put into the fuel tank, it can usually be cleaned. If the tank is rusted internally, it should be replaced.

PROCEDURE:
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1. Disconnect the negative battery cable.
2. Drain the fuel tank, refer to Powertrain Management/Fuel Delivery and Air Induction/Fuel Tank/Service and Repair.
3. Remove the fuel tank.
4. Remove the inline fuel filter, and inspect for contamination. If the filter is plugged, replace it. (Leave the fuel line from the fuel pump to the filter disconnected.)
5. Move the tank away from heat, flame, or other source of ignition. Remove the fuel sending unit assembly and inspect the filter sock. If the filter sock is contaminated, a new filter sock should be installed when reassembled.
6. Complete draining the tank by rocking and allowing the fuel to run out the access hole.
7. Purge the fuel tank, refer to FUEL TANK PURGE.
8. Disconnect the fuel feed pipe and use air pressure to clean the fuel line and the fuel return line. Apply air pressure in the direction fuel normally flows through the line.
9. Use low air pressure to clean the pipes on the fuel sending unit.
10. Install the fuel sending unit assembly, with a new seal, into the tank and install the tank. Connect the fuel sending unit wires and all fuel pipes.
11. Connect a hose to the fuel pump discharge line, left previously disconnected, and insert the other end of the hose into an empty 1 gallon can.
12. Connect the battery cable.
13. Put 23 liters (six gallons) of clean fuel in the tank and crank the engine to pump two liters (two quarts) of fuel into the can. This will purge any contaminated fuel from the fuel pump.
14. Remove the hose and connect the fuel line. Use new clamps on all fuel line connections.
15. START the engine and check for leaks.