FUEL FILTER ELEMENT REPLACEMENT
The fuel filter element has the following replacement steps:
1. Loosen the fuel tank filler cap to release pressure or vacuum.
2. Remove the threaded nut for the filter element from the filter housing, using hand pressure or a strap wrench.
3. Remove the filter element from the filter housing and clean the sealing surfaces.
4. Position and install the new filter element, using hand pressure to seat the sealing surfaces.
5. Install the threaded nut, tightening it with hand pressure.
6. Bleed air from the filter housing in these steps:
– Open the air vent valve on the top of the filter element.
– Position a shop towel under the filter housing.
– Disconnect the fuel shut-off solenoid B+ wire (pink) from the injection pump.
– Crank the engine for 10 to 15 seconds to fill the filter housing with fuel (if necessary, wait one minute and crank the engine again).
– When clear fuel exits the air bleed valve, close it and wipe any spilled fuel from both the filter housing and the engine.
– Connect the injection pump fuel shut-off solenoid B+ wire.
7. Start the engine, allow it to run for five minutes and check for fuel leaks.
WIF SENSOR DIAGNOSIS AND REPLACEMENT
The WIF sensor has a diagnosis procedure related to the WATER IN FUEL warning, alerting the vehicle driver.
When this occurs, use the following procedure:
1. Drain the fuel filter housing by doing these things:
– Stop the engine.
– Place a container under the drain valve exit hose at the left front side of the engine.
– Open the drain valve.
– Start the engine and operate it at operating speed until clear fuel appears at the drain valve exit hose.
– Close the drain valve.
2. Observe the WATER IN FUEL warning lamp:
– If it is OFF, end the diagnosis.
– If it is ON, do the following things:
• Remove the fuel tank filler cap to release pressure or vacuum.
• Remove the two fuel filter assembly mounting bolts.
• Separate the electrical connector for the WIF sensor.
• Remove the WIF sensor mounting screws, and pull the sensor from the filter housing.
• Wipe the tip of the WIF sensor to remove water.
• Install the WIF sensor (with a new O-ring seal) and mounting screws.
• Attach the WIF sensor electrical connector.
• Install the two fuel filter assembly mounting bolts.
• Install the fuel tank filler cap.
• Follow the filter housing air bleeding procedure (page 7-19, steps 6 and 7).
3. Once again, observe the WATER IN FUEL warning lamp:
– If it is OFF, end the diagnosis.
– If it is ON, follow the WIF sensor replacement procedure in Step 2.
FUEL HEATER DIAGNOSIS AND REPLACEMENT
The fuel heater has the following diagnosis and replacement procedure:
1. Remove the fuel tank filler cap to release pressure or vacuum.
2. Remove the two fuel filter assembly mounting bolts.
3. Separate the inlet, outlet and drain hoses from filter housing fittings and cap both the hose and fitting ends.
4. Separate the electrical connectors for the WIF sensor and fuel heater.
5. At a workbench, remove the fuel heater threaded nut, using hand pressure or a strap wrench.
6. Remove the fuel heater from the filter housing and clean the sealing surfaces.
7. With the fuel heater at 70° F (21° C), connect its B+ and ground wires to a 12-volt battery.
8. Observe the heating element (no heating should occur).
9. Cool the sensor part of the fuel heater, using ice.
10. With the fuel heater below 46° F (8° C), wet its heating element with fuel and connect its B+ and ground wires to a 12-volt battery for 30 seconds.
11. Observe the heating element (heating should occur).
Note: If heating does not occur, replace the fuel heater.
12. Install the fuel heater (with a new O-ring seal) in the filter housing.
13. Install the threaded nut for the fuel heater, using hand pressure.
14. Attach the WIF sensor and fuel heater electrical connectors.
15. Remove the fitting and hose end caps and install the inlet, outlet and drain hoses on the filter housing.
16. Install the two fuel filter assembly mounting bolts.
17. Install the fuel tank filler cap.
18. Follow the filter housing air bleeding procedure (page 7-19, steps 6 and 7).
