Pressure regulator?

[mightymoose_22]

Someone verify my thinking before I spend any money please :P
I previously asked on here if anyone had removed the fuel pressure regulator without removing the whole intake, and with that feedback and with having shoved my face up in there to get a good look I am sure I can do it.

I just have to go buy the dumb thing and replace it.

So... the car stalls when idling and warm. It's not anything EGR or PCV related. I haven't replaced the fuel filter, but I seriously doubt it is plugged up since the car runs fine... just doesn't idle for me anymore

So anyway... I was unable to locate a vacuum leak, so I disconnected the hoses from the vacuum port on the intake. The engine will run fine with the port plugged up and does not stall, but after adding things back on it will run rough and stall shortly after the hose for the fuel pressure regulator is connected.

I've checked the hose and it has no leaks. The pressure regulator also held pressure when applied with a hand held pump.... so still no leak, but something is going screwy when it is connected.

With the engine running I had a little over 35psi in the fuel lines, which is normal...

So I am at somewhat of a loss... any thought on why my engine dies with the fuel pressure regulator connected?

[mightymoose_22]

Hmm... all that said... what's the odds that there is no vacuum leak, but that the regulator is simply worn and is activating at a lower pressure than it used to? It is the original part from 94...
hmm... maybe if I get the right kind of gauge I can check that... I've been cheating with a tire pressure gauge so far :P

[Anavel]

Since your car dies with the regulator connect you could have a worn or broken spring in the regulator, low fuel pressure, maybe a clogged fuel filter or worse, a bad fuel pump.

[Davescort97]

If it runs fine with the regulator disconnected and assuming you plugged the vacuum line going into it, it sure seems like the most likely culprit of your problem. What do you think about disconnecting it and driving that way if it works fine in that mode?
You can get a fuel pressure regulator for $20 and $3 for new o ring and gasket. I can't tell you for sure it is the regulator causing your problem. I wish I could. If it were me, I would give it a good kick just to let it know who's the boss and then I would replace it.

[mightymoose_22]

I tried kicking it... that is often my first choice. Didn't work though, so I tried replacing it... no luck.
It must be a fuel problem somewhere but I can't locate it. When everything is disconnected from the intake port (and plugged) it runs fine. Adding things back one at a time it's fine until the fuel pressure regulator is attached... then kaput.
I think the regulator is doing just fine now... but for some reason the car doesn't want to run at idle... which I believe is when the fuel is on low pressure.

I guess it could also be a funky sensor.... I don't think my MAF is too old, and I would have different symptoms with an IAC problem.

Hmm... I need to sleep on it... will get back to it later :P

[mightymoose_22]

Well I think I had a vacuum leak all along... I had hooked up the gauge and tested everything I could think of and found no leaks... pressure was right about 20... but with a length of hose today I was listening all around the engine and believe I located a leak either from the bottom side of the intake manifold or from the cylinder head.

Unmetered air... that's about all there is too it. Unplugging the vacuum from the pressure regulator was just allowing the engine just enough fuel to keep running in spite of the leak. It sure made it seem like a regulator issue, but no. I can't tell which gasket the leak is coming from so I will just replace both. Hopefully that does the trick.