Problem with fuel system voltage

[1992awdlaser]

Well my car now has another problem. I picked up my car from the tranny shop after getting a clutch put in it and was driving home then it cut off. I called my boss and he brought me some gas to see if that was the problem, nope. I got it towed to my work then got it looked at they said it needed a fuel pump because the pressure was 8 psi at the fuel filter. No prblem the pump had a warranty so I got it replaced for free. But that wasnt the problem. The car still wont start and what we know is. The voltage at the maf is 7.9 volts. The voltage at the fuel pump relay is 13 volts when cranking. And the voltage at the pump is 2 volts when cranking. I think that it is in the wiring somewhere but dont know.

 

[Quasimondo]

If this is through the stock harness, just rewire it and call it a day.

 

[1992awdlaser]

Well we directly wired the new walbro pump to my battery to bypass all the wiring and it is still at 8psi of fuel at the fuel filter. I checked to see if I had any kinked fuel lines that might be restricting flow but I didn't see any. So we think that the walbro I bought is bad.

 

[Quasimondo]

I thought you replaced the fuel pump. You're going to replace it again?

 

[1992awdlaser]

I thought you replaced the fuel pump. You're going to replace it again?

I did but the walbro pump I bought was bad and it was brand new from dsmparts. I bought the same walbro pump before this one and it was bad to. I don't know if it is my car or the walbro pumps from dsmparts but neither of the two worked on my car even though stock ones do. I took out this walbro put in an advance pump and the car started right up.

 

[skelly]

Two bad Walbro's in a row? Doubtful. I'd suggest testing the voltage at the pump with the pump disconnected. That should give you an idea of what the vehicle is providing at that point without any voltage drop from an attached device usch as the electric pump motor. If you're still at 2 volts then that's definitely the issue with the fuel pressure and thereby the problems with starting. 2V just ain't gonna cut it.

- SK

 

[1992awdlaser]

I will try it just to see what happens, but like I said the OEM pump from advance worked just fine.

 

[skelly]

...the OEM pump from advance worked just fine...

Hmm I missed this statement back there it still seems unlikely that two new pumps are bad. I hope you don't think Walbro's are bad pumps as a result of this experience because they really are pretty good. I'd be curious to know:

A) What's the fuel pressure at the filter with the Advance pump running, and

B) What's the voltage reading on the Advance pump?

I was wondering if perhaps the Walbro is over-powering a border-line failing stock FPR, but the voltage drops you're seeing coimbined with the successful use of the Advance pump would seem to indicate otherwise.

- SK