Hi,
My car has developed a random stumbling miss that i can't pinpoint, and datamaster isnt showing anything. My plugs are less than 3k old, and my wires less than 30k. I noticed when i got in my car today that the fuel pump kept running when i turned the key to the on position. Normally it runs for 2-3 seconds and stops. I just turned the key and let it run, and after about 45 seconds, it stopped. I turned the key again, and it did the same thing, the whole time changing pitch and not sounding right.

With 130k+ on the car, could my fuel pump be causing all of my problems?

I'm going to go drive around for a few minutes, logging with datamaster, and see if anything shows up.

Thanks,
-David-

 

Yea, definetly sounds like its time for a new pump.

 

If I could find some software that'll run on a laptop with my ALDL cable, and detect a misfire like the dealers can, I could tell for sure. If no missfire shows, my finger would point to the fuel pump.

 

it could be your fuel pressure regulator or another fuel leak maybe

 

I'm not losing fuel anywhere, infact, i'm getting good gas mileage.
I tried pulling the vacuum line off of the regulator, if it's bad fuel would have sprayed out, wouldn't it?

 

yeah sounds like your fpr is fine

is your car hard to start?

 

IMO, it wouldn't be the pump's fault if it stayed on more than 2 seconds with just the key ON. It would have to be getting voltage from somewhere to make it stay on. Maybe the f/p relay is sticking, or it is getting a faulty signal from the PCM.

Maybe the relay is flaky and also dropping out during the engine running and causing loss of pressure.

 

I have a spare relay (the one under the dash), and I tried switching them. Is there another relay anywhere else?

I captured a datamaster log while i was driving around earlier if anyone would like to take a look at it...
http://69.93.44.42/~cam94z28/datamas..._and_trans.uni

 

so it still continues to run with a different relay in it?

you ar going to need to see if teh relay is open or closed so you can go from there.

 

I just went outside, and tried again, if i let it run for 45 seconds or until it stops, then start the car, and turn it off, it will only run for a few seconds, it's like it's losing pressure over time.

I don't know how i would check if it's open or closed.

 

you will need a testlight or a multi meter to est the relay. with the key on engine off check for hot on the pink wire. you should also have a ground on the vlack/white wire. the computer sends the hot signal to close the relay through the dark green/white wire at witch time hot will go out the relay through the grey wire to the fuel pump. for the hell of it look and make sure that no one hooked a hot feed to the fuel prime connector under the hood.


see what the relay is doing with the key on and if it;s alwasy sending power or not