fuel pump problems - Third Generation F-Body Message Boards

K-slice · 07-30-2009, 09:30 PM

So my fuel pump went out the other day and the shop I go to said it was gonna cost $500 for the job. A guy I know (ASE and Michigan certified) said he'd do it for barley over the cost of parts so I let him do it.

I got the car back yesterday and there is this loud whine coming from the rear end, I assume it's the pump since i messed with the exhaust and other stuff back there and nothing made a difference. Plus my gas gauge always reads well above full even though I've driven 100 miles since I got the car back with less than a full tank. I took the cluster apart today and pushed the needle down but upon starting the car again it went right back up as far as it could.

I don't know if these 2 problems could be related or not. Maybe just let it go for a while and see if it gets better? I dunno?

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BigBadLou · 07-31-2009, 09:24 AM

These two problems could be very well related.
The fuel gauge shares the same wiring harness as the fuel pump. Your friend might have accidentaly disconnected/cut the fuel sender wire (pink) by the fuel tank, causing the gauge to read Full (it reads full when there is a break in the circuit).

Lou

K-slice · 07-31-2009, 09:31 AM

He told me since the pump was a newer style he'd have to rewire it... It came with a little harness and stuff to do this. I'm not sure I see how having that wire cut could make this noise, could you please explain. And what will I need to do to fix it?

tony_cogliandro · 07-31-2009, 10:55 AM

what kind of pump did he put in? some make noise - a lot of noise.

BigBadLou · 07-31-2009, 12:42 PM

Also, if he put in an external pump, it's outside of the tank now and the noise is not muffled by the tank or its contents. That would add to the noise level as well.

Lou

K-slice · 07-31-2009, 02:56 PM

well, i know somethings wrong now. When I was driving downtown i hit a stoplight. when it turned green I puth the pedal down pretty good. It reved up to 2K then went down to 1500 and wouldnt go any higher. I let off a little and it returned to 2K as I went towards home it onlt got worse. By the time I got home if I gave it any gas the rpms would drop and the car start to die.
So basicy its almost doing the same thing it was before the new pump...

BigBadLou · 07-31-2009, 03:37 PM

Quote:

Originally Posted by K-slice

So basicy its almost doing the same thing it was before the new pump...

Which begs the question: how did you determine the first time that your fuel pump was bad?
Time to put a fuel pressure gauge on the fuel rail to see how much you're building up.

Lou

K-slice · 07-31-2009, 11:22 PM

I had the shop diagnose it, didn't charge me for it. Just had a new regualtor put in last year so I don't know how that coulkd be bad. followed both fuel lines down the frame and to the injectors, didnt see any pinches.
I drove the car again tonight and it was fine when i left but when I got to my destination it has acting up again, same thing on the way home. It runs good for a miles then starts to act like its not getting enough fuel..

BigBadLou · 08-01-2009, 12:01 AM

I say again, put a gauge on the fuel rail to see what is really going on. Something tells me you'll find out real quick.

A shop can say you need a new fuel pump (gives them a $500 job) but don't ask me how many times I've seen shops give out false diagnosis just to make some money.

Lou