Wild Fuel Pressure readings


New Member
Sep 18, 2003
A few months ago, I installed an Accufab adjustable fuel pressure regulator and gauge for the fuel rail. Over the past month, I've noticed that each time I go check the FP, the reading can vary 5-10 psi. For example, set to 42psi line off, car runs OK , then gradually KRs grow...I check FP again, and it reads 37 psi. What gives? I actually contacted Accufab and had just removed it, planning to return for diagnosis. But, I re-installed the Bosch (38 psi fixed) that came with the car and noticed that it was reading 44 psi - 6 psi higher than it should be!!

I've tried three different gauges, that's not the problem. Could it be the return line is clogged? If so, what's the best remedy?

Any ideas? Thanks.
I ran into this problem myself.Most guys will tell you to blow out the return line or look for kinks.
I tried that with no luck.
Although I did get the F/P manageable,I suspect it's the flex connection at the bottom front of the engine[going to the chassis from the engine,jack up the car,you'll see it at the bottom of the engine].
If the standard methods of clearing it don't work,you may want to call Jack Cotton and see about replacement pieces.
He has them in Stainless[last I checked].
Do them both.
Rubber hose does deteriorate over time,especially with the alchohol enhanced fuels.
Thanks, looks OK in there

Thanks for the advice - I did check out the flex lines up front, removed the connection and cleaned it out, and blew air through the whole return line system. Even checked out the rubber connections by the tank (covered by heat shield) and they looked OK too.

Went out and ran it a few times, and the FP showed some fluctuation at first, but since then, it's solid. Hopefully if anything was in there, it's been dislodged. Fingers crossed - if not, maybe it's time to replace and reroute that return line.

Happy holidays!