fuel pump problems

[sblack13]

trying to fix my friends car,

at first i thought the problem was the pump. Tried using the walbro outta my 240 which worked fine. Worked for a bit, then now the walbro will only pump for about 1-2 seconds after the key is turned.

we tried swapping the relays by the battery still nothing,

and fuel pump just turns on and turns back off immediately. We hooked 2 wires from the fuel pump to the battery of the car and the fuel pump worked fine...So there must be a problem with the cable that the fuel pump connects to or theres another problem that wont let the fuel pump stay on...

anyone have a similar problem?

[sblack13]

oh and the fuse is fine, and when we swapped fuel pumps we swapped the whole assembly w/ the top cover and wire w/ the blue plug.

[sblack13]

anyone?? i can't seem to understand the problem.

[pwhitersxs]

Seems like your wiring is bad going to the fuel pump and might not be getting the proper voltage. Test to see if you are getting the proper voltage in the wire. Get a fuel pressure gauge to see if your base fuel pressure is ok, the pressure should be around 40 psi when the car is turned on. Since you said the pump worked fine once you gave it a straight connection to the battery, a cheap way to test it out and to drive around would be just to do what you did and wire it straight to the battery and put a switch in there so you could turn off the fuel pump. This way you could see if you are getting good fuel pressure and would provide 12v vs 10v (stock wiring is too thin and provides resistance and it is old).

Another way around dealing with bad fuel pump wiring may be to hard wire your fuel pump. Look at http://deatschwerks.com/ and instead of using your fuel pump wire for power, use the wire off of the cigarette lighter for the relay since this wire will turn off once the car is shut off. Hope this helps.

[sblack13]

ok i saw the gas tank was almost empty. So we put 1 gallon of plus gasoline still nothing. I need your expert opinion.

[the head]

hot wire the pump and see if it works
when you say it only runs for a bit do you mean you try to start the car? because if you just flip on the ign it will quit running after 5 sec