Fuel Pressure Swinging From 60-100 psi??
 

On the drive in this morning I noticed my fuel pressure guage (added) seemed to be reading 100 psi. The next stop light I got to I shut the truck down and restarted it and it came back to 60 psi where it normaly stays. Thoughout the rest of the drive in the pressure would swing form 60-100 and seemed to be some what associated with the position of the skinny pedal on the right. It was a little cold here this morning (18 F) and was wondering if that may be what is causing the swing or could this be a sign of an up comming problem?

Any suggestions welcome,
Thanks in advance.

Engine temp. might have something to do with it. If the engine has not reached proper operating temp. it could require additional throttle to respond which equates to higher pressure demand.

The pump is regulated by a spring, so there is no more demand for higher or lower fuel pressure, it is whatever that spring will hold. It should be 55psi plus or minus 5. My guess is you possibly have a grounding issue with the gauge. I highly doubt you're seeing 100psi of fuel pressure, you will start popping o-rings if that was the case.

yea what Mdub707 said it sounds like a gauge to me.

That could be the case I was behind the fuse block the other day messing with the upfitter switches. Could have possibly tweaked something the wrong way?

Thanks to all for the great info. I have been keeping a closer watch on it and My guess is it is probly something to do with the guage or associated components. I haven't had a chance to open it up to know for sure though. The truck still runs as good as it has been and I am seeing no other issues except for the fuel guage being stuck on 100 psi.

UPDATE??
 

:argh:Still no change in the situation. I have checked my wiring connections and all seem good. I have been in touch with the AutoMeter folk and they are starting to show some intrest.

Anyone have an idea about what OE equipment may be causing this problem, if any? And how to go about checking that equipment?:humm:

I am Stumped...:s:
W.R.

Problem Fixed.... It was the sending unit after all.

Good to hear. I have a ISSPRO EV2 fuel pressure gauge, and it swings pretty drastically too, not as bad as yours though. However I'm reading fuel pressure about 36" past the end of the heads down on the vegistroke manifold. Not sure if my pump just can't keep up or what.