CEL 2-3-1 - fuel pressure at 35lbs.. What now??!

[icelandic]

About 100k miles ago, I had low fuel pressure symptoms, and clearly the fuel pressure regulator was at fault. I replaced it and problem was solved. I did not throw out the old one. I found out that it was holding vacumm Ok, so I decided to try to clean it up. I put carb cleaner on the vacumm side and let it sit for a few hours. A lot of crud came out. Put carb cleaner again, and lots of black particulated material came out. I knocked the vacumm port on a hard surface and some more material came out. Put carb cleaner in one more time, and some more material came out. After that, several thousand miles later, when doing a PCV replacement, I decided to put the old unit in place, out of curiosity. It is still there, working perfectly. What I learned is that somehow maybe air with oil vapours get in there when the engine is turned off, and it hardens with time, making the diaphragm movement more difficult. So if your FPR still holds vacumm, that might be your problem. If it were totally faulty, you would be loosing fuel pressure very quickly after shutting down the engine, which appears not to be what is actually happening.

Icelandic

[Ozark Lee]

Thanks for the great tip icelandic. I had not heard of a method or repairing them before. When they no longer hold vacuum they normally suck raw fuel back through the vacuum line but that doesn't seem to be Mike-Halewai's situation at all.

...Lee

[Mike-Halewai]

Thanks Icelandic.. I will give this a try, I'd love to be able to save the money on it. What would you estimate to be the total time taken to complete this "maintenance"?

[icelandic]

I remember I left it filled with carb cleaner overnight.

[icelandic]

Mike,

On a second thought, remember that the clean up procedure will only work if the diaphragm is ok. Check if it is holding vacumm before you go on. And clean both sides with the carb cleaner.
Icelandic

[Mike-Halewai]

Icelandic the regulator did hold vacuum pressure fairly well as I recall. I think I'll drop it into the parts washer and see what happens after a couple of hours.

Thanks again.

[icelandic]

Mike,
Did the fpr clean up work out for you fuel pressure problem?
Another investigation line if it doesn´t, is the possibility of a leaky fuel injector. If that is the case, the engine would not run perfectly smooth, and milesge would be bad. Besides the low pressure, you never mentioned running symptoms.

Icelandic

[Mike-Halewai]

The engine runs like a champ. With the exception of strange hesitation when climbing even the smallest if hills or pulling out to pass. I'm hoping that once I get to the fpr and a "holy" turbo hose that issue may go away. Well see what happens this weekend with the fpr.

[Mike-Halewai]

Well last night I pulled the Throttle Body, EGR and FPR off for a romantic night with my wagon. I bathed the horribly dirty throttle body in the parts washer (it had so much carbon and crap stuck to it, it didn't open with out enough pressure to unstick it from the sludge).

The EGR looked very dirty, I cleaned it with carb cleaner and replaced the gasket (and outside of being a PITA to get back in... all went well).

The FPR regulator looked clean as a whistle, cleaned it with carb. cleaner as well, sprayed it let sit for quite some time, and then repeated this for the next 2 hours.

Car still does it peculiar hesitation bit under moderate throttle and beyond. Didn't have enough light to check the FP when I was done, but I suspect it will be exactly the same.

[Mike-Halewai]

Alrighty... (I know that alrighty isn't a word...) so last post for this problem hopefully; replaced the FPR with a used unit from a 95 855T and it seems that accleration is really smooth, no struggling fuel delivery... so we'll see....