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Posted by: championgt1 Jul 27 2009, 12:07 PM

I am trying to diagnois a fuel pump problem. I know the relays are good and when i jump a wire from the front left pin to ground and turn the key on the pump runs. If it is disconnected and the connector is plugged in it does not. Where does the white wire for this pin go to?

Posted by: underthetire Jul 27 2009, 12:09 PM

Goes to the ECU. ECU runs it with key on only for a second or two. Doesn't run the pump again until cranking/running.

Posted by: championgt1 Jul 27 2009, 12:17 PM

So it is safe to assume that there is a problem with that wire somewhere between the board and the ECU? Or is the ECU a possible problem?

Posted by: ahdoman Jul 27 2009, 12:23 PM

Check your fuses on the board as well. One of them is for the fuel pump and can become corroded.

Posted by: underthetire Jul 27 2009, 12:24 PM

I don't have the pin out for the ECU connector here. Could be either. You can remove the connector on the ECU and ground it there to test it. Could be a bad driver in the ECU. Could even be a connector problem on the ECU, or a bad trace or solder joint. I never opened my ECU, I got rid of it.

FYI just make sure your not chasing something that is not really the problem. I think the pump only runs for 1 second when you turn the key on. Kinda hard to tell.

Posted by: underthetire Jul 27 2009, 12:26 PM

True, however by grounding the pin he has eliminated that possibility. But for sure check it anyway.

Posted by: championgt1 Jul 27 2009, 12:38 PM

I just pulled the ECU out and traced the wire from the connector on the relay board to the ECU. With my tester is shows continuity and with the key on shows 12 volts. It seems like that is correct.However I have the fuel line from the pump going to a glass bottle and it is getting no fuel in the bottle unless I jump the pin to ground.

Posted by: underthetire Jul 27 2009, 12:43 PM

Sounds correct. You are seeing the 12 through the coil of the relay. My guess is you have a bad ECU. Can't hurt to open it and see if anything is visibly wrong. Or see if anyone close to you has a ECU you could try.

Posted by: championgt1 Jul 27 2009, 12:46 PM

underthetire thanks for all your help and quick responses. There is a member local to me with a rebuilt ECU sitting in his garage. I will swap them out and see what happens.

Posted by: underthetire Jul 27 2009, 12:55 PM

No problem. I actually have to go work now anyway. Good luck.

Posted by: Jeff Bowlsby Jul 27 2009, 02:16 PM

This may help:

http://members.rennlist.com/pbanders/FPChecklist_frame.htm

Posted by: sixnotfour Jul 27 2009, 02:22 PM

RicD just had the same problem switched out the ECU, works now.

Posted by: championgt1 Jul 27 2009, 11:18 PM

Problem found. It's running again.

Thanks everyone.

Posted by: underthetire Jul 27 2009, 11:35 PM

Well?

Posted by: SirAndy Jul 27 2009, 11:58 PM

Posted by: championgt1 Jul 28 2009, 10:22 AM

FYI just make sure your not chasing something that is not really the problem. I think the pump only runs for 1 second when you turn the key on. Kinda hard to tell.
[/quote]

This was the problem all along. A member brought over a remanufactured ECU and we plugged it in. He could here the relay click and the pump run. Ok, ECU is bad. Just to be sure we plugged my ECU back in and again he could here the relay click and the pump run.

The problem all along was that by myself in the car I could not here the pump run and thought there was an actual problem, when there was not.