Low fuel pressure!!! HELP!!

[powerram250c]

Hello, Our farm truck (early 1999 f250 4x4 auto) has been starting harder and idling rough. Glow plug circuit is in good shape. I checked fuel pressure at the fuel bowl and it's running around 42 psi idling after installing a new fuel lift pump on the frame. Old pump only ran about 20 psi. My question, is there a relief valve for excess fuel or regulator that allows the fuel to return to the tank? If there is, this one might be partially stuck open. The CEL is not on and there are no other abnormal dash lights are on either. -Kevin

[jesilvas]

There is a fuel pressure regulator on the side of the fuel bowl.
Replacement O-rings for Ford Diesel Engines
Replacement O-rings for Ford Diesel Engines
You could buy either of those kits to see that's your issue. First one is an upgraded housing that just allows you to change your pressure to what the truck likes. The second is just the OEM rebuild kit.
Other option would be trash in the pick up foot/tube in the fuel tank. I'd drop it first, clean it out, and maybe to the Hutch/Harpoon mod to it if you wanted too. It's cheaper doing that first. Then, if it is the FPR, then you can get either kit.

[audiocontr]

Purchase the stock fpr replacement. It is a must have for any truck over 100k. See my sig.

Fpr is NOT monitored by the ecu. No codes possible.

[jesilvas]

Why the stock replacement? Why would it not be desired to be able to change the pressure dependent on what the truck likes best?
And what about having a superior FPR housing? We all know how easy it is break the old one. Just wondering why stock is better at this point?

[audiocontr]

Because its not the spring that wears, its the poppet. The housing replacement only replaces the housing, not the poppet. You can search my posts for pictures to see the difference. In all honesty, it was Bob from Diesel O'rings who explained what wears and which kit to buy.

Best choice is both i guess, but as long as you're careful with the housing you should be fine with stock replacement. I'd also use the stock spring which comes with the stock kit. It gets you to about 70 psi brand new.

[powerram250c]

Sweet, to me that sounds like my problem. I'm going to pull the fpr off and look at it this weekend. Thanks for helping me out.

[powerram250c]

Okay after some work and thinking, I first replaced the fuel pump. Brought my fuel pressure up to 42 psi from about 30 psi. Next the fuel pressure relief valve's rubber poppet seat was torn and not allowing the fuel bowl to hold pressure. Temporary fix was an o ring. That brought my pressure up to about 52 psi. Bought a fuel pressure relief rebuild kit from dieselorings.com and installed it and now my fuel pressure runs about 73 psi idling. Truck now starts and runs perfect. This was the answer to my problem. Thanks for the input guys!!!

[audiocontr]

Wish other folks would do the same. Super common problem.

[RockinT]

Reading this thread and talking to Bob at DieselORings worked for me. Two mechanics told it was my pump. Bob called b.s. My pressure is up from 40 to around 70 with no wasted money on a new pump.

[powerram250c]

What a deal. That's why I love working on things like this, cause you learn all the different ways problems can be solved.