Hello, I am new to the forum but not to the world of diesels. I have a 2001 Ford F250 with the 7.3 powerstroke. I have a question regarding my fuel pressure.

Over the winter I developed a pretty bad leaky fuel bowl and I repaired it with guzzle's rebuild kit and while I was at it I installed a set of ISSPRO guages for Fuel pressure and HPOP pressure.

Today I noticed that when I let my truck prime during the WTS it sounds like the fuel pump is taking for ever to build up to around 60psi and as soon as the pump stops my pressure falls steadily to zero. I'm wondering if anyone else had this problem, I'm thinking it is either the Fuel pump itself(isn't there a check valve built into it) or it could be my FPR but any information would be greatly appreciated!

Can anybody help??

Thank you

 

Welcome to FTE. The FPR is just a spring operated plunger that closes off the return line with enough pressure to hold a higher psi. Yes the fuel pump has a check valve, but as soon as the pump shuts off, all the fuel returns to the tank through the FPR and return line. It's completely normal and how the system was designed.

 

I can attest to this. I recently added a fuel pressure guage to see what I was at after the FPR rebuild and riffraff Frx. I think mine might be a little low. I installed the recommended gold spring. I get 59-61 as soon as I turn the key and driving. If I do not start and the pump shuts off; it will drop to zero.

If I punch it from a red light I can get my pressure to drop down to 50psi, not sure if thats normal. Normal cruising pressure is 60 give or take a lb. I thought it should be higher with gold springs, IDK

 

Okay that makes some sense. When I rebuilt the bowl I did not change the spring so it's all still stock. I've only had the gauges a few months and I'll pay closer attention. I thought the pressure held after the pump shut off before start, but mine runs like yours around 60-65 at idle and 50-55 at WOT. I was almost kind of hoping it was something like a fuel pump problem to also help explain my crappy gas mileage. In short of sounding like a conspiracy Nut it seems like ever since the government screwed with our fuel it's dropped like a rock, when I first got the truck I would get 20mpg mix and 24mpg on long road trips, now I'm lucky to get 14mpg mix and 18 mpg on road trips.

Thanks for the input!

 

I do not think it would effect mileage that much, but our winter fuel makes me lose 2-2.5 mpg. There are items which can cause poor fuel mileage, ie: ebp sensor/tube, possibly IPR, CPS, and some others.

I have been fighting low boost, high egts, and crappy mileage. I get 10 winter/12-12.5 summer. I swore I got better mileage when I first got the truck but my dumb *** did all my mods without monitoring.

I do not get better mileage on the HW either. I always go the same mileage to a tank. slow, fast, city, highway. I agree with you on the gov't screwing us on fuel though.

 

I do have the autoenginuity program to check all my sensors but I never found anywhere what the numbers should be reading to tell me if it's good or bad. The fuel mileage has kinda got me by the nuts when I first bought the truck I got 440 miles on 22 gallons of fuel, easy math, but over the last few years I've been struggling to get 320 on 24 gallon of fuel. No leaks and the truck runs beautiful. This last winter I didn't even break 300 on 22-24 gallons of fuel. I love my truck to death but it's getting to the point I'm thinking about selling my hot rod to buy a gas car that gets better mileage.

Thanks for all the responses, keep the ideas coming!