See Figures 1 and 2
The fuel pump, used on the Tempo/Topaz fuel injected engine, is mounted on a fuel sender assembly inside the fuel tank. The fuel tank has an internal pump cavity in which the fuel pump and sender assembly rest. This design provides satisfactory operation during most vehicle operating conditions (Ex: Steep altitudes with low tank fill level).
REMOVAL & INSTALLATION
- Disconnect the negative battery cable.
- Relieve the fuel system pressure.
- Remove the fuel from the fuel tank by pumping out through the filler. Use care to prevent combustion from fuel spillage.
- Raise and support the vehicle safely.
- Disconnect and remove the fuel filler tube.
- On all wheel drive vehicles, remove the exhaust system and rear axle assembly.
- Support the fuel tank and remove the fuel tank support straps.
- Lower the fuel tank partially and tag the fuel lines. Unplug the electrical connectors, then the vent lines from the tank. Finally, remove the fuel tank from the vehicle.
- Clean any dirt from around the fuel pump attaching flange so that it will not enter the fuel tank during removal and installation.
- Turn the fuel pump locking ring counterclockwise, and remove the locking ring.
- Remove the fuel pump and bracket assembly.
- Remove the seal gasket and discard.
- Clean fuel pump mounting flange and fuel tank mounting surface and seal ring groove.
- Lightly coat the new seal ring gasket with a suitable lubricant compound part No. C1AZ-19590-B or equivalent, to hold the gasket in place during installation.
- All wheel drive vehicles only, install the jet pump assembly and retaining screw.
- Install fuel pump and sender. Ensure that nylon filter is not damaged and that locating keys are in keyways and the seal ring remains in place.
- All wheel drive vehicles only, connect the jet pump line and electrical connector to the resistor. Ensure locating keyways and seal ring remain in place.
- Hold the assembly in place and install locking ring finger-tight. Ensure that all locking tabs are under tank lock ring tabs.
- Secure the unit with locking ring by rotating ring clockwise using fuel sender wrench tool D84P-9275-A or equivalent, until ring stops against stops.
- Remove the tank from the bench, and move to the vehicle, then support the tank while plugging in the fuel and vent lines, as well as the electrical connectors to appropriate places.
- Install tank in vehicle and secure with retaining straps.
- All wheel drive vehicles only, install rear axle assembly and exhaust system.
- Lower the vehicle and refill the tank. Check for any leaks.
- Connect the negative battery cable.
- Check fuel pressure.
- Remove the pressure gauge, start the engine and recheck for fuel leaks. Correct all fuel leaks immediately.
The jet pump is an additional feature equipped on these vehicles. It is designed to provide adequate fuel supply during extreme conditions. The jet pump is installed next to the fuel pump.
- Lower the fuel tank as explained.
- Loosen fuel pump using an appropriate wrench.
- Partially lift out the sending unit. Unplug the jet pump line and electrical connector to the resister.
- Remove the fuel pump and bracket.
- Remove the jet pump retaining screws.
- Remove jet pump.
- Install jet pump assembly using retaining screws tightened to 10-15 ft. lbs. (4-20 Nm).
- Install the fuel pump.
- Plug in the electrical connector and the pump line.
- Install the fuel tank.
See Figure 3
- Check that the tank contains an adequate supply of fuel.
- Make certain the ignition switch is OFF .
- Check for any signs of fuel leakage at all fittings and lines.
- Locate the inertia switch in the luggage compartment.
- Unplug the electrical connector from the inertia switch and connect a continuity tester to one of the leads at the wiring harness. Check for continuity between either of the wires and ground.
- If continuity is not present at either wire, the fuel tank must be removed from the vehicle and continuity must be checked between the wiring harness and the switch leads.
- If the leads check okay, check for continuity across the pump terminals.
- If no continuity is present across terminals, then replace the fuel pump and sender assembly.
- If continuity is present across the pump terminals, check the ground circuit or the connections to the pump form the body connector.
- Reconnect the inertia switch. Attach a voltmeter to the wiring harness on the pump side of the switch. (This would be the side which did indicate continuity).
- Observe the voltmeter reading, when the ignition key is turned to the ON position. The voltmeter should read over 10 volts for 1 second and then return to zero (0) volts.
- If the voltage is not as specified, check the inertia switch for an open circuit. The switch may need to be reset. If okay, check the electrical circuit to find fault.
See Figure 4
This test requires the use of a pressure gauge tool (T80L-9974-A or equivalent), which is attached to the diagnostic pressure tap fitting (fuel diagnostic valve). It also requires that the fuel system relay be modified, using one of the following relays: E3EB-9345-BA, CA, DA or E3TF-9345-AA.
- Open hood and install protective covers on the front fenders.
- Relieve the fuel system pressure.
- Disconnect the fuel return line. Try to avoid fuel spillage.
- Connect a hose from the fuel return fitting to a calibrated container, at least 1 qt. (906 g) minimum volume.
- Attach the pressure gauge between the fuel charging unit (Central) or the fuel rail (Multiport) and the fuel filter.
- Locate the fuel pump relay (behind the glove box or near the EEC module around the steering column) and remove it. The ground lead should be brought outside the vehicle and located nearby.
- Using the appropriate relay indicated above, modify the relay case by drilling a 1 / 8 in. (3.1mm) hole and cutting the skirt as indicated in the diagram.
- Add a 16-18 gauge jumper wire between pins 2 and 4, as outlined in the diagram.
- Add 8 feet 2 m) of flexible wire through the hole in the case to point B, as shown. Add a ground to the end of the added wire.
The leads should be soldered in place and as close to the base as possible, to permit insertion of the relay into socket with minimum interference.
Energize the fuel pump by jumper the ground lead from the relay for 10 seconds. Check the fuel pressure while energized. If there is no pressure, check that there is voltage pass the inertia switch. Correct, if necessary.
- The gauge should indicate a reading between 3-16 psi (90-10 kPa).
- Check that the fuel flow is at a minimum of 6 ounces (178 ml) in 10 seconds and fuel pressure remains at a minimum of 1.6 psi (80 kPa) immediately after shutdown.
- If these conditions are met, the pump is operating properly.
- If both pressure and flow conditions are met, but pressure will not maintain after shutdown, check for a leaking regulator or injector. If both check okay, replace the fuel pump.
- After testing, replace the modified fuel pump relay with the original relay.
Generally any faults related to the electric fuel pump will result in a loss or reduction of fuel flow and/or pressure.
Exercise care when disconnecting fuel lines or when installing gauges, to avoid fuel spillage.
Unless otherwise stated, turn OFF the fuel pump relay at the conclusion of any tests, by disconnecting the jumper or by turning the ignition switch OFF .
On vehicles equipped with all wheel drive, the following conditions may be an indication that the jet pump is not functioning properly.