There are two different electric fuel pumps used:
See Figure 1
The fuel pump is mounted to the fuel sender assembly inside the fuel tank. The fuel is pumped to the engine at a specified flow and pressure by the fuel pump. Excess fuel is returned to the fuel tank by the return pipe. The fuel pump delivers a constant flow of fuel to the engine even during low fuel conditions and aggressive vehicle maneuvers.
Removal & Installation
- Disconnect the negative battery cable.
- Properly relieve the fuel system pressure.
See Figure 2
- Drain and remove the fuel tank.
- Remove the fuel sender assembly.
- Disassemble the fuel pump strainer and the fuel pump: Note the position of the strainer in relation to the pump.
See Figure 3
Support the fuel pump in one hand, and grab the strainer in the other hand.
- Rotate strainer in one direction and pull off pump. Discard strainer.
See Figure 4
- Remove deflector.
- Disconnect the fuel pump electrical connector.
- Loosen the two connecting clamps, if equipped.
Place the fuel sender assembly upside down on the work bench.
- Pull the fuel pump downward to remove it from the mounting bracket, then tilt the pump outward and remove it from the connecting hose or the fuel pulse dampener.
- It is recommended to replace the hose and clamps, if equipped.
- Push the fuel pump assembly into the attaching hose. Attach the pump electrical wires and fasten the hose clamps to the attaching hose and around the pump body, where equipped.
- Place the fuel tank sender and pump assembly into the fuel tank. Use a new O-ring seal during assembly.
See Figure 5
- Properly relieve the fuel system pressure and install a pressure test gauge according to the tool manufacturers instructions.
Turn the ignition switch to the
position for 3 seconds, then turn to the
position for 5 seconds. Repeat this procedure two or three times to pressurize the system. Again turn the switch to the
- On TBI equipped vehicles, the gauge should read a static pressure of between 9 and 13 psi (62-89kPa)
- On SFI equipped vehicles, the gauge should read a static pressure of between 41 and 47 psi (248-325kPa)
- If not, check for a clogged fuel filter, a kinked fuel line, or an inoperative fuel pump.
- On TBI equipped vehicles, the fuel pressure will drop after the fuel pump stops running due to a controlled bleed in the fuel system. Use of the fuel pressure gauge will determine if the fuel system pressure is enough for the engine to start and run.
- No fuel spray from the injector indicates a faulty fuel or ignition system or no PCM control of the injector.
- This test will determine if the ignition control module is not generating the reference pulse or if the wiring or PCM are at fault. By touching and removing a test light to B+ on CKT 430 (purple/white wire from the ignition system), a reference pulse should be generated. If the injector test light blinks, the PCM and wiring are OK.
See Figures 6 and 7