I was driving around the other day and happened to look up at my fuel pressure gauge and noticed my fp had dropped from 52-54 cruising to 50. Well it had me wondering so I got on it and fp jumped to 58 at wot but then all a sudden fell off to low 50s so I stayed out of it and went home parked it. Any ideas why this happened? Bad regulator maybe? It is the stocker. I have a walbro 255 in tank and 38lbhr injectors. It's been fine until know.

 

Seems weird that the pressure went up when you stepped on it. Do you have a Magnavolt, boost-a-pump, or something like that? What is your battery voltage doing?

 

Walbro 255 in tank is all. No boost a pump of any kind. Didn't really pay attention to the voltage at the time

 

I just replaced my fuel pressure gauge and transducer for a improper reading issue... so don't rule out the gauge. May want to tap in a known good gauge to compare. Then look at the regulator. Good luck.

 

Thanks for the heads up. Ill try that

 

Pressure should jump when you step on it. Its the vacuum referenced fuel pressure regulator. Low manifold vacuum=high fuel pressure, high manifold vacuum=low fuel pressure. Its why idle pressures are always lower than WOT or when you rapidly open the throttle.

peace
Hog

 

Oops, Hog is right. If you have referenced boost it will increase.

 

So why would it just now start falling off? Before it would stay...any ideas on what to do?

 

Have you checked your fuel filter? when you remove it and dry it out, you shoud be able to blow through it. If you have to strain to blow throgh it, get a new one.

 

Haven't checked it but it's only been on there about 2,000 miles.