ProtoCab

I connected a fuel pressure gauge to my left fuel rail test port and found that my fuel pressure at idle is approx 43psi.

This is excessively high and I was wondering what effect this will have on my mixture & CO levels.

BTW, I don't run an O2 Sensor.

If I disconnect the vacuum feed to my FPR, the fuel pressure does not rise and if I reconnect it, it does not drop.

I only noticed this high fuel pressure has started happening after I replaced a malfunctioning Fuel Pressure Damper, which was bleeding excess fuel into the vacuum line leading to the throttle body and FPR

Could the gasoline have blocked or stuffed up my FPR?

It doesn't seem to be doing a very good job of regulating the fuel pressure to a more "sane" level

J. Brinkley

I'd first get a new fpr is it's old, maybe check for kinks in return line, but how random would that be?
what if your old damper was good, dumping excess volume from over pressured lines? leading you to think it was bad when the fpr was the actual bad part.
just thinking.

ProtoCab

Jerry, the old damper was totally stuffed. I removed the vacuum connection from it, fired up the car and it was literally p!ssing fuel out of the vacuum port. This caused the car not to idle because fuel was being dumped into the intake at the rear of the throttle body and it was flooding the engine. After I replaced the damper, the car fired up properly after a few goes of clearing out the excess fuel sitting in the combustion chambers.

But now, I have the problem that my fuel pressure is too high and my car is running too rich. As I said above, if I disconnect the vacuum to the FPR, there is no change in fuel pressure at all. It should increase without vacuum, and drop with vacuum connected.

Either I have a blocked vacuum connection at the FPR, or the FPR is screwed.

Can the FPR be removed with the engine in place, or is this an engine drop thing?

J. Brinkley

if you remove the the bracket that holds the three sensors, CHT etc, the FPR is pretty easy to get out. no lowering or anything. maybe open up the return line in the front and check.for fuel delivery?

ProtoCab

Thanks Jerry. I'll tackle it asap. It may well be easy to remove, but I can imagine putting it back in there is going to be a b!atch!