Fuel pump fail

[marcusg0085]

My fuel pump keeps failing, will work for a while but after a day or so will go out.
Getting power to the pump but will not kick on. What can cause it to fail?

[Manolito]

Please clarify. Are you saying that you replaced your fuel pump and the new unit lasted only a day or two?

The tank looks clean when you open it? No sign of water or other contaminants in the bottom? The sock on the bottom of the pump is not clogged with debris?

My long shot guess is related to the fact that fuel pumps are made to operate in a non-conductive liquid. Is it possible that your fuel has something dissolved in it that causes it to conduct electricity?

[marcusg0085]

the sock is clean. the place were I bought the pump told me to check the cram and can sensor. were are these located?

[Frajo]

Check the connection at the pump.

[Manolito]

So I take it that when you first turn the key to the On position, you don't hear the usual 2 second spin-up of the fuel pump?

If you have a voltmeter or a 12V test light (which you can make from an old tail light bulb), attach it to the plug and make sure you are getting power to the fuel pump for the first two seconds after you turn the key to the On position. The ground wire should be brown and the hot wire to the pump should be green/violet (or green/something). You may need a helper to turn the key while you test for power at the pump.

If you don't think you are getting power to the fuel pump, you can try hot-wiring it using an old cigarette lighter adapter from one of your broken electronic devices. I used an old cigarette lighter adapter a few weeks ago to hot-wire the fuel pump on a '97 that has been sitting in my garage for years. I pumped all the old fuel out through the fuel rail, and refilled the tank with fresh fuel.

"cram and can sensor" don't mean anything. Might they have said "crank and cam sensors"?

A failed crank position sensor can keep the car from starting. A failed cam position sensor will make the car run poorly but will not keep it from starting. You seem pretty certain, however, that the problem resides with the fuel pump so I would keep working that angle. If you hear the fuel pump but are not getting fuel pressure at the fuel rail, you may need a new fuel filter. Instructions are here http://www.frontiernet.net/~papi/Filter.html

[marcusg0085]

I don't hear the pump come on at all. I drove the car home frome the mechanic, left the car alone for 2 days and nothing I am getting power to the pump. what i did notice when i drove the car home the fuel gauge was not working, also the temp gauge. My car is a 1994 318i.