Bad Fuel Pump?

[arcticguy57]

Hello All, I've got a 92 Explorer with a 4.0, 5 speed. Recently, when I go to start it, I don't hear that familiar "whirring" sound from my fuel pump. If I turn the ignition switch on-off a couple of times, it makes that sound, then the vehicle starts. I replaced the fuel pump relay and it still does the same thing. Could it be my ignition switch? Thanks in advance.

 

[MrShorty]

Could it be my ignition switch?

Yes a bad ignition switch is one possible cause of the symptoms you are describing. Of course, there are several other possible causes, too.

When you turn the key on and the pump doesn't run, does the check engine light come on indicating that the main computer is getting power?

If the computer is getting power, then the next thing I would do would be to get out my voltmeter and wiring diagram. Then, starting at the battery, work down the fuel pump circuit until the voltage drops (ground fuel pump test lead to close relay). Where the voltage drops is where the problem is.

If the computer isn't getting power, then I would do the same thing only follow the wires leading to the computer. (this is where you would eventually end up finding a bad ignition switch).

 

[arcticguy57]

Mr Shorty, I've been researching this great forum and I think it mightbe the PCM relay. Where exactly is that located? Napa quoted me a price of $125.00 for it. Does that sound right? Thanks

 

[BrooklynBay]

That might be the price for the entire PCM. The PCM relay should be about the same price as the fuel pump relay. Check any auto parts store in your area.