Truck has been parked for almost a week, but fired it up tonight to pick up a pizza. Noticed my fuel pressure was about 85 psi ( normally 70-75 ) after a short drive of maybe 20 mins the pressure was creeping up to 100...
I've already done my search homework, and will be busting knuckles tomorrow to get her fixed, but I have to make a trip in the am and I'm wondering if it will be ok for the drive, or should I leave it parked. I'm sure it can only get so high, but will I be doing any damage making an hour round trip
I pulled my 5'r 880 miles last week without a mechanical hiccup, shredded the belt and now this since I got home.....at least I can say she got me home before she gave out.
I love this truck....

 

Hey Frank,
Good luck on the Fix , and on another note kinda OT, You back in NC yet?

 

Hey Rich, I'm back home in Fl now, left Nc last week for a few week break. I'm supposed to be back up next week, but I may be going to Texas instead......my job changes by the minute. I'll keep you in the loop if and when I head your way.

 

Gimme a shout if you head down to my neck o' the woods.

 

OK that sounds good, would like to try another GTG at bills BBQ when you get back up this way.

 

Yes & yes

 

Frank,
In case it helps any...I have experienced high fuel pressure readings on two occasions. The first time it happened, I would start my truck and the fuel pressure would be 80-ish and then it would slowely creep upwards until the needle pegged. Event duration was about 5-10 minutes. Turned out to be a faulty fuel pressure sender.

The next time, the symptoms were a little different. My fuel pressure was 70-ish for about a week, then in the 80s for about a week, then 90s and so on...
Eventually the pressure was around 95-100 psi full time. A new FPR cured the issue on that occasion.

When I was attempting to diagnose each issue...I remember watching the gauge during WOT runs and noted the pressure reading did not drop when the sender was faulty but would drop to around 85-90 psi when the FPR was acting up.

Hopefully this info will help you diagnose your issue.
Good luck and drive safe.

P.S. I drove around for weeks with 100 psi fuel pressure before I found the fix.

 

Good luck. When I removed my fuel bowl to clean it up and remove the fuel bowl heater, I had the little piece in the upper left corner of this pic fall out.


The o-rings was worn and this piece would slide up and prevent the FPR from working properly somehow. My pressure was getting so high that it was causing the fuel pump to cycle off and on and off and on, etc. I don't know where it maxed out at, but you could hear it cycle on and off when you turned the key on.

I got the FPR rebuild kit from Bob and got it to hold steady down near 100 psi, but finally had to give up and cut the spring down to get my fuel pressure back down to where it should be. Note: If you cut the spring down, file the cut edge of the spring so the sharp barb doesn't hand up inside the plunger momentarily and give you a false (high) reading. (learned that the hard way)

Hopefully you have better luck than I did.

 

Thanks Greg, my pressure will drop at wot (down to 75-80) then creep back up. And if I cycle the key on no start after a few seconds the pressure drops down to around 30.
Looks like fpr time .

 

Thanks Chris, I rebuilt my bowl and fpr about a year or so ago, and no matter what spring I installed in my FRx I held 75 psi, so its possible I did something wrong back then

 

I don't know. I was convinced my problem had to do with the FRX since my pressure problems started when I installed the updated version. Removed the FRX to rule that out. Pulled the return line and stuck a hose on the FPR that dumped into a coffee can, pulled the intake and ran a hose from the back of the fuel pump into a can of diesel to eliminate the fuel tank as a possibility.

 

I contributed mine to the FRx as well, first gen. Mine creeped up past 80psi and had no choice to cut the spring too. Got her down in the mid/high 60's, and then once i installed my wvo system, i used the FRx line to feed the wvo, and "capped" the barb from off the FPR housing. With it capped and 1-coil cut, my pressure was 52/54psi..To correct it, i cut 1/2-coil and added a B.B., now sit'n a steady 69/70psi. BUT, for the first year, the gauge with FRx installed was always around 69-72psi...

 

Well, I changed out my poppet, poppet seat, poppet beveled oring, tried all three FRx springs, blew out my return line and I'm still sitting at 100 psi....

If I cycle the pump engine off it will slowly drop to about 55 psi.
Wot it will dip to 95 for a second then back to 100.

I'll have to get it down to my shop this week and try to figure it out. So much for enjoying my vacation

 

Should drop all the way down to zero psi....
What does the gauge read with key on, engine off, fuel pump timed out and fuel bowl empty?

If you get any sort of pressure reading, then your sensor is suspect.

http://www.isspro.com/TROUBLESHOOTIN...leshooting.pdf

 

Key on, engine off, pump timed out and fuel bowl empty I'm holding a solid 50 psi Greg. Looks like your right on the money with a faulty sending unit.
My blood pressure just went down as well
Thanks bro