Hello I got a problem with my 89 GTA 5.7 TPI. I just got done replacing the injectors, and the fuel pressure regulator. I got the injectors from fuelinjectorconnection.com they are the 24 lbs injectors Bosch Design III. The regulator is a Gp-Sorensen kit.

So the problem is its not holding fuel pressure after shut off and when the car is running it idles real rough. Also while its running its running at about 34 PSI at the rail. The leak down rate is fast! I can watch it go down in a matter of mins. The 1.5 secs it primes it will jump to 10 psi and then after 10 secs waiting to prime the fuel pump again it will jump to 44ish or higher PSI and when it turns off it jumps down to 35ish and leaks down real fast. The pump is new and the fuel filter is new, both where replaced this year.

To me it sounds like regulator problems. The regulator came with a bunch of O-rings. Other than the injectors I don't see any O-rings to replace that I took off. Also when I took off the regulator cap thing I saw no O-rings under it at all, I don't know if there should be. So I just put the new one in and put the cap back on. Did I miss an O-ring or could I have put the cap back on wrong? Maybe the spring isn't in it right?

I did have a small gasoline fire but it didn't damage any thing I had to use water to put it out and I was real careful when I put water on the fire not to get it in my open intake. but I think a little got in the 1, and 3 injector holes I forgot to look out for them but it was not much. I don't think the water could get past the closed valves right? I Also cut down the injector mounts 1/4 inch because of the smaller Injector. I did burn a new chip telling the ECM the injectors are 24 lbs injectors and that was the only change I did to the chip.

Any help is greatly appreciated. Oh yeah and the car is not pulling any codes.

 

Pull vacuum line off fuel press regulator (FPR) and see if any gas is getting into vacuum line. If so, the press regulator diaphram is bad.

On fuel press bleed-down test, pinch the return fuel line ,where it is rubber, with some smooth jawed pliers and see if the bleed-down press check gets any better. If fuel press holds with line pinched shut, the FPR is leaking internally.

If you suspect water got into intake runner or combustion chamber. Pull the plugs and crank it over a few times.

 

I took off the vacuum line and none came out and I didn't smell any in the hose.

I pinched the line and it jumped to 70 psi and when I let it go it goes down to 42 or 40ish and I knew it would do that. So what I did was pinch the line let it jump up to 70 psi let it go and pinch it again so I can see how long it takes pinched and unpinched at the same psi. It is definitely dropping a lot slower when its pinched in the last 10 mines its only dropped 3 psi about. So if the regulator is leaking internally how do I fix that? did I just install it wrong?

The car has ran so I don't think the water is still in it anymore.

 

I'm not familiar with the Gp-Sorensen kit, but sounds like something is wrong inside.
Do they have a website that shows a pic of the internals?

 

Here is a link to where I got it from it just shows the diaphragm and not the O-rings

http://www.autozone.com/R,APP294296/...ductDetail.htm

It’s new but I can’t seem to get it to seal up. I took off the cap today and tried to see how I could have put it on wrong and to see if it ripped or any thing I didn't see any thing wrong. So I put it back on and it’s still losing pressure.

Do you know of a good fuel pressure regulator you would suggest getting?

 

The autozone replacement should work fine, I just put one on my car a couple months ago, with no problems. It's just a spring and rubber diaphragm, but that's really all there is to a fuel pressure regulator. There aren't any o-rings between the cap and regulator body, you just sandwich the rubber diaphragm between them. I don't really see how it could be put together wrong, it's pretty straightforward, and only fits one way. It could be something with the fuel pump or pulsator. Try priming the system to pressure and pinching the fuel feed line, not the return line, and see if it still bleeds down fast. That will figure out if the fuel is leaking back through the inlet line.

 

Yeah I don't see how I could mess it up its very simple. Sense my old one could hold pressure a lot better than this one I kind of doubt it's anything to do with the pump but I'll do that test just to make sure but I don't think I fully understand how to do the test. So I put the fuel pressure gage on the rail, pressure up the system, pinch the feed line, and see if it drops. If it drops than the regulator is bad and if it doesn’t it’s the pump or the pulsator. Right?

I also need to make sure I'm pinching the right lines. The hard line coming from the passenger side rail is that the feed line? And the line coming from under the regulator is the return line? I some how got my self confused on this and I know it’s a dumb question...