In the power distribution box there is afuel pum prelay check that for good connections as well as corrosion. From there it goes to the pcm and #40 sends the signal to the pcm #80 goes from teh pcm to the pump. Anyone of those places could be a bad connection. But you have to find out where the car is not getting power to the fuel pump first. Good luck on this one it sounds like a screwed up wiring harness someplace.
Fuel Pump, Electric Explorer
The multiport fuel injection (MFI) system uses a fuel delivery module with integral reservoir. The module is a reservoir which also houses the pump and valving. This design provides satisfactory
operation during extreme vehicle maneuvers and steep vehicle climbing with low tank fill levels.
The fuel pump (9350) is mounted inside the module/reservoir assembly inside the fuel tank (9002). This assembly includes a check valve which is in the outlet of the fuel pump. The function of this valve
is to maintain pressure in the system after the vehicle is shut down. The pressure retention helps prevent hot starting problems. This fuel pump is capable of supplying 95 liters (25 gallons) of fuel per
hour at 310 kPa (45 psi). The fuel pump has an internal pressure relief valve which limits the maximum fuel pump pressure to 850 kPa (125 psi). This only takes effect if there is a system blockage,
causing system pressure to rise too high. The system pressure is controlled by a pressure regulator on the engine (6007).
The fuel pump is protected at its inlet by a nylon pickup element. This nylon element filters dirt and contaminants which could plug or damage the internal pump components while at the same time
allowing passage of small quantities of water which may accumulate within the fuel tank sump.
The electrical system has a fuel pump control relay controlled by the powertrain control module (PCM) (12A650), which provides power to the fuel pump under various operating conditions. When
the ignition switch (11572) is in the OFF position, the contacts of the PCM power and fuel pump relays are open.
When the ignition switch is first turned to the ON position, the PCM power relay is energized, closing its contacts. Power is provided to both the fuel pump relay and a timing device in the powertrain
control module. The fuel pump runs through the contacts of the fuel pump relay and the inertia fuel shutoff switch (IFS switch) (9341). If the ignition switch is not turned to the START position, the
timing device in the powertrain control module will open the relay ground circuit (No. 926 LB/O) to the relay after approximately one second.
Opening the ground circuit de energizes the fuel pump relay (opening its contacts), which turns the fuel pump off. This circuitry provides for pre pressurization of the fuel system.
When the ignition switch is turned to the START position, the powertrain control module grounds the fuel pump relay to provide fuel for starting the engine while cranking.
After the engine starts, the ignition switch is returned to the ON position, and power to the fuel pump is again supplied through the fuel pump relay. The powertrain control module senses engine speed
and shuts off the fuel pump by opening the ground circuit to the fuel pump relay when the engine stops or is below 120 rpm.
Also has the fuel filter ever been changed? I have no further suggestions on this.
Thursday, August 2nd, 2012 AT 7:16 PM