Fuel System Cleaning Procedure

The following procedure covers disassembly, inspection and cleaning of the complete fuel supply system. If the fuel system is contaminated it can be cleaned. The extent of the fuel system contamination can usually be determined during disassembly.

NOTE: Special tools are required for fuel line separation. Use J 37088 fuel line separator Set or equivalent.

PROCEDURE

1. Disconnect the negative battery terminal.
2. Relieve fuel system pressure. Refer to FUEL SYSTEM PRESSURE RELIEF.
3. Remove in-line fuel filter. Refer to COMPONENT REPLACEMENT AND REPAIR PROCEDURES/FUEL FILTER. Inspect fuel filter for contamination. If the filter is plugged or contaminated, replace it after fuel system cleaning is complete.
4. Drain the fuel tank and remove it from vehicle. Refer to COMPONENT REPLACEMENT AND REPAIR PROCEDURES/FUEL TANK ASSEMBLY.
5. Place the fuel tank in a suitable work area away from heat, flame or other sources of ignition.
6. Remove the fuel level meter assembly. Refer to COMPONENT REPLACEMENT AND REPAIR PROCEDURES/FUEL PUMP/FUEL GAUGE SENDING UNIT.
a. Inspect the fuel pump filter. If the filter is contaminated or plugged it must be replaced and the fuel tank should be cleaned.
b. Inspect the fuel pump inlet for dirt and debris. If found, the fuel pump should be replaced.
7. Flush the fuel tank with hot water for at least 5 minutes. Pour water out of the fuel pump/fuel sending unit opening. Rock the tank to be sure that removal of water in the fuel tank is complete.
CAUTION: If nylon fuel feed or return lines become kinked or damaged in any way, they must be replaced. DO NOT attempt to repair sections of nylon fuel lines. No repairs can be made. Replace fuel lines if damaged.
8. Disconnect quick-connect fittings at the engine compartment fuel feed and return lines.
a. Grasp both ends of one fuel line connection and twist 1/4 turn in each direction to loosen any dirt in the quick-connect fitting. Repeat for other fittings.
WARNING: Safety glasses must be worn when using compressed air, as flying dirt particles may cause eye injury.
b. Using compressed air, blow out dirt from all quick-connect fittings before removing.
c. Choose the correct tool from J37088 tool set (or equivalent) for the size of fitting.
d. Insert tool into female connector, then push inward to release male connector.
e. Repeat for other fittings.
9. Using compressed air, apply air pressure to fuel lines in the opposite direction from normal fuel flow.
a. Inspect all connectors for dirt and burrs. Clean or replace component/assemblies as required.
NOTE: If it is necessary to remove rust or burrs from the male tube end of a quick-connect fitting, use emery cloth in a radial motion with the tube end to prevent damage to the o-ring sealing surface.
b. Using a clean shop towel, wipe off male tube ends.

WARNING: To reduce the risk of fire and personal injury: Before connecting fuel line quick-connect fittings, always apply a few drops of engine oil to the male tube ends. This will ensure proper reconnection and prevent a possible fuel leak. (During normal operation, the o-rings inside the female connector will swell and may prevent proper reconnection if not lubricated.

10. Apply a few drops of clean engine oil to the male tube ends of the fuel feed and return lines.
11. Connect fuel line quick-connect fittings:
a. Push connectors together to cause the retaining tabs/fingers to snap into place.
b. Once installed, pull on both ends of each connection to make sure they are secure.
12. Install in-line fuel filter. Refer to COMPONENT REPLACEMENT AND REPAIR PROCEDURES/FUEL FILTER.
13. Install the fuel pump/fuel gauge sending unit. Refer to COMPONENT REPLACEMENT AND REPAIR PROCEDURES/FUEL PUMP/FUEL GAUGE SENDING UNIT.
14. Install the fuel tank assembly. Refer to COMPONENT REPLACEMENT AND REPAIR PROCEDURES/FUEL TANK ASSEMBLY.
15. Add fuel and install the fuel filler cap.
16. Reconnect the negative battery connector.
17. Turn ignition switch to the ON position for two seconds, then turn to the OFF position for five seconds. Again, turn to the ON position and check vehicle for fuel leaks.