The fuel filter should be replaced, immediately, upon evidence of dirt in the fuel system. Regular replacement of the fuel filter should be every 3,000 miles. If the engine seems to be suffering from fuel starvation, remove the filter and blow through it with compressed air to see if it is clogged. If air won't pass through the filter easily, or if dirt is visible in the inlet passage, replace the filter.
A backup wrench is an open end wrench of the proper size used to hold a fuel filter or fitting in position while a fuel line is removed. A flared wrench is a special hex wrench with a narrow open end allowing the fuel line nut to be gripped tightly. A regular open end wrench may be substituted if used carefully so the fitting is not rounded.
The fuel filter on non-EFI models contains a screen to minimize the amount of contaminants entering the carburetor via the fuel system. The fuel filter on the non-EFI models is attached to the carburetor.
The EFI fuel filter provides extremely fine filtration to protect the small metering orifices of the injector nozzles. The filter is a one-piece construction which cannot be cleaned. If the filter becomes clogged or restricted, it should be replaced with a new filter. The filter is mounted on the right fender apron.
REMOVAL & INSTALLATION
See Figures 1, 2 and 3
On these vehicles, the fuel filter is located on the fuel line to the carburetor. Special care should be taken when removing and installing the fuel filter, not to bend or distort the fuel line in any way.
- Remove gas cap to relieve any pressure that may be present in the fuel system.
- Remove the air cleaner bonnet assembly.
- Using a backup wrench on the return line fitting on the top of the fuel filter, remove the fuel line with a flare nut wrench.
- Using a backup wrench on the fuel filter inlet fitting, remove the fuel line from the fuel filter with a flare nut wrench.
- Using a backup wrench on the fuel filter outlet fitting, loosen the fuel line and remove the fuel filter from the engine with a flare nut wrench.
- Apply a drop of engine oil to all the fuel line nuts and flared ends.
- Position the fuel filter with flow arrow on the filter directed towards the fuel line going to the carburetor.
- Finger-tighten the fittings at the fuel filter outlet, inlet and return line into the top of the filter.
Using a backup wrench on the fuel filter fittings, tighten the fuel lines in the following sequence:
- Tighten the outlet and inlet line nuts to 15-18 ft. lbs. (20.0-24.0 Nm)
- Tighten the nut on the return line at the top of the filter to 6-9 ft. lbs. (15-18 Nm).
- Inspect the fuel lines and carefully adjust if they are interfering with the carburetor, air pump, or fuel filter housing.
- Start the engine and check for fuel leaks at all the connections. Retighten if necessary.
- If removed, install the air filter bonnet assembly.
See Figure 4
If the vehicle is equipped with a pressure relief valve, install an EFI/CFI fuel pressure gauge T80L9974B or equivalent and depressurize the fuel system. If the vehicle is not equipped with a pressure relief valve, the fuel filter connection should be covered with a shop rag or towel to prevent the fuel from spraying during the removal procedure. It is also possible to reduce the amount of pressure in the fuel system by locating the inertia switch (usually located in the luggage compartment) and disconnecting the electrical connection on the inertia switch. Next crank the engine for 15 seconds to reduce the system pressure.
Fuel injected vehicles use steel fuel lines and nylon fuel hose assemblies with push connect fittings. This type of system requires special removal and installation procedures. Refer to the procedure "Push Connector Fittings" when necessary.
- Disconnect the negative battery cable.
- Properly relieve the fuel system of any pressure.
- Remove the push connect fittings according to the "Push Connector Fittings'' removal and installation procedure. Install new retainer clips in each connector fitting.
The flow arrow direction should be noted to ensure proper flow of fuel through the replacement filter.
- Remove the filter from the bracket by loosening the filter retaining clamp enough to allow the filter to pass through.
- Install the filter into the bracket, ensuring the proper direction of flow, as noted earlier. Tighten the clamp to 15-25 inch lbs. (1.7-2.8 Nm).
- Install push connect fittings at both ends of the filter.
- Connect the negative battery cable.
- Start the engine and inspect for leaks.
See Figure 5
The fuel filter/conditioner must be serviced (water purged) at each engine oil change (7500 miles) interval. To purge water from the system:
- Make sure the engine and ignition switch are OFF.
- Place a suitable container under the fuel filter/conditioner water drain tube under the car.
- Open the water drain valve at the bottom of the filter/conditioner element 2 1 / 2 -3 turns.
- Pump the prime pump at the top of the filter for 10 to 15 strokes, or until all of the water is purged from the filter, and clear diesel fuel is apparent.
If the water/fuel will not drain from the tube, open the drain valve one more turn or until the water/fuel starts to flow.
- Close the drain valve and tighten.
- Start the engine and check for leaks.
- Make sure that the engine and ignition are OFF.
- Disconnect the water level sensor harness located at the bottom of the filter element.
- Using an appropriate filter strap wrench loosen and remove the filter element from the top mounting bracket. Clean filter mounting surface.
- Carefully unscrew the water drain valve/sensor probe from the bottom of the element. Wipe the probe with a clean dry cloth.
- Unsnap the sensor probe pigtail from the bottom of the filter element and wipe with a clean dry rag.
- Snap cleaned probe pigtail onto the new filter element.
- Lubricate the two O-rings on the water sensor probe with a light film of oil. Slowly screw the probe into the bottom of the new filter element.
- Lubricate the sealing gasket of the new filter with oil. Screw the filter element onto the mount adapter. Hand tighten, then back off to the point where the gasket is just touching the adapter. Retighten by hand and an additional 1 / 2 - 5 / 8 turn.
- Reconnect the water level sensor harness.
- Prime the fuel system by pumping the primer handle until pressure is felt when pumping.
- Start the engine and check for fuel leaks.