The problem that I am having is the car not wanting to stay running, I have a fuel pressure gauge on the and noticed that the fuel pump would prime 43psi at rail then when the fuel pump stops running the fuel pressure would bleed down to 0psi in seconds. I have tried WOT then start, it starts and runs for a second or two and dies. It seems like something is holding the injectors open and loading the motor with fuel. we have tested for a leaky injector and all seam fine, The injectors are the resigned bosh ones have 3k-4k miles on them.
New
walbro 255 fuel pump with hot wire kit
Plugs
O2's

 

Sounds more like the fuel return line. IIRC, there's supposed to be a check valve to stop too much fuel from returning to the tank and thus maintaining the pressure.

 

I would look into a new fuel pressure regulator. Sounds like its shot.

 

A bum FPR won't bleed pressure completely that quickly.

 

The fuel pump is bad, it should hardy bleed any pressure once primed.

 

I would look into the fuel pump also......if you are getting 43 when it primes the fuel reg is working only way you will get fuel pressure. Pump quits and loose pressure sounds like it might be going back through the fuel pump.

 

The fuel pump has less than 500 miles on it. Would the PCM see low fuel psi and open the injectors to compensate for it? I ask this because once it runs it fouls out a set of plug.

 

Do you have an aftermarket regulator on it, like Aeromotive? Those were real good for leaking internally sending fuel through the vacuum line which will bleed down fast and foul plugs.

Did the car ever run right with this setup? I had a LOT of trouble with pcmforless mailorder tunes before I stopped using them so do not assume the tune is good unless the car did at some point run right since the reprogram.

 

^^ the FPR is stock, yes the car ran great,

 

I'm bettin the clamp on the fuel pump needs to be retightened. It has come loose and is allowing pressure to bleed back through.

 

Where did you get the Walbro? There have been kits out there that came with hose not rated for submersion they split and leak internally to the tank after some time.

Not all fuel line can handle full submersion.

That is one of the nice things about Racetronix kit, it uses a stock style teflon hose.

 

I got the fuel pump kit strait from Racetronix, took the fuel pump back out and tested it, no leaks

 

Fortunately pressure dropping that fast can only be caused by a few things.

Stuck open injector(s).
Faulty fuel pressure regulator.
Leaking return line.
Split or broken fuel line inside the tank.
Bad fuel pump check.

All of which are fairly easy to test.

There is no check valve on the return line other than the fuel pressure regulator.

 

I got back from the shop and now he thinks that the fuel pressure gauge that i have on the car is bad, the car is trying to hydro lock the motor, we are stumped by this

 

Do you mean fuel is dumping into the cylinders?

 

It sounds like the fuel pressure gauge is ok and that you have a leaky injector or two if the engine is trying to hydro lock.

 

SS RRR yes Alot of it, we have tried two different sets of injectors, with no changes

 

Have you physically pulled up the fuel rail and watched which injector(s) are the culprit?

 

Walbros don't have check *****..... they will bleed down once primed. If it is making the corrxt amount of pressure while the pump is running I would look elsewhere for your issues.

 

If it is hydrolocking the engine then you need to look at injectors or the regulator leaking through the vacuum line. That is REALLY easy to look for. With a COLD engine, pull the vacuum line and see if there is fuel, if there is BINGO, if there is not cover the fitting with a paper towel and prime and see if it gets wet.

Do not do this with a hot engine and I would cover the fitting when priming to catch any possible spray.