very weird fuel pressure problem

[chris90]

94 camaro 3.4; fuel pressure rises to about 20 psi when key is turned, but falls quickly back to 0 psi. If timed right, I can get it started and it idles fine at about 20 psi. As soon as I give it gas, it stumbles; yet if I give it gas slowly, I can cruze down the road at 75 mph with no problem(cept if I gas it suddenly, then it hesitates.) Oh, and the fuel pump and pressure regulator were replaced 2 months ago. wtf. any ideas? would leaky injectors be the problem?

[cuda_dude]

sounds like a junk pump to me

[cuda_dude]

was the fuel filter replaced when the pump was?

[chris90]

filter was also replaced...don't think its the pump cause it primes fine, system just won't hold pressure when primed, but will hold at 20psi when running. ( figured out how to get it started watching the pressure gauge; before it falls back to 0psi).

[ikeyballz]

how about something like a fuel-pump-relay? like a fuse.. the auto resets. maybe when it hits ~20psi the fuel pump overloads, causing the fuse to trip..thats why when you hit the acc hard, it causes the fuel pump to load again.


try switch that.. it COULD be the prob, makes sense to me..

how abt neone else?

[Morley]

Originally Posted by chris90

system just won't hold pressure when primed, but will hold at 20psi when running. ( figured out how to get it started watching the pressure gauge; before it falls back to 0psi).

Then either you were sold a pump without an internal check valve or the one in the pump is shot already. If it went bad that quickly then I would question weather the pump itself was junk.

[chris90]

wow...finally got it fixed. It was the rubber hose on the pump(in the tank)had come loose at the clamp and wasn't holding the pressure. After I pulled the fuel rail and injectors I primed the system and they didn't leak a drop. A lot of work for a simple problem...but isn't that the way it usually goes.lol