87rattler

Here's the symptons...PRE-SWAP-After priming and driving, the fuel pressure drop to 0# immediately after shutdown...also gas odor in the crankcase. Swapped in new injectors and tested for leaks...after prime, the pressure was 42#s, and after key off, down to 9#s and slowly went to 4#s in a few minutes...20 minutes later still at 4#s. Plenum and runners are still off...FPR vacuum hose isn't connected...Seems to be no leaks and at least it holding pressure now.

Question is..does this seem normal or is there something I'm missing..I've read that the pressure should slowly drop over time.

Sorry if this is covered in other threads, but I'm getting my driveway repaved this week and need this to be done.

LilSki

iTrader: (1)

I don't think that is correct but I will say I am not running a stock ECM as I am running a megasquirt.

But my car will prime to 43#s and when I shut it off it will stay around 35#s for a long time. I left the pressure gauge on it overnight and I still had like 15#s.

87rattler

thanks lil ski, i am probably going to swap a new FPR and hope that sorts it out.

87rattler

When i put in new injectors, and had just the fuel rail on top of my manifold, it would hold pressure. Now after putting everything else back on, it won't hold pressure, at all. The car sat for over a week as i waited for injectors. Put them in and it would somewhat hold the priming pressure, as i tested for leaks. Once i got everything back on, i started it up and ran it for a while and once i shut it down, 0#s immediately. Now when i prime, it will go to 0#s immediately.

No fuel odor from FPR when vaccuum is unplugged and pressure increase around 5 #s.

Could this be a cold start injector leak. It didn't leak while i was just priming it to test the fuel rail for leaks. Could it leak for a while after it is used. Can I shut it off by disconnecting it.

Or any ideas on something else.

LilSki

iTrader: (1)

Anything is possible. You can remove the cold start injector for testing but you will have to plug the back of the fuel rail with something.

Johnnygeek

I wouldnt worry about fuel pressure bleed off
of it may be back flowing to the pump into the tank.


but I guess you can hot wire the pump relay so pump stays on for a bit and look for fuel leaks.
The Leak could be anywhere in the fuel line from top of the tank to the injector O-rings

darbysan

I would bet on the Cold Start injector. When I got mine, it was frozen OPEN. I sent it off for repair, but they could not fix it. I would try unplugging the CSI and see if that helps with the pressure. It will start without it until it starts to get cold outside again. Easy to program around deleting it.