Fuel pressure to high?

Andys04f350 · Sep 17, 2012

I put in the upgraded blue spring in my 04 a couple months back. No that its getting colder out the fuel pressure is getting high. Cruising on the highway it reads 95-100 at 60-70 miles an hour. If i stand on it full throttle it will drop down to 80-85. If i read correctly before, fuel pressure should be 65-75 with the blue spring upgrade?

Gary · Sep 17, 2012

Yes your fuel pressure should be 65-75 psi, are you measuring it at the port on the fuel filter housing? I don't know what you could have done wrong but maybe take the cover off at look at it, that would be the first place I would look.

Big Angry Hillbilly · Sep 18, 2012

Unless you have the calibrated fuel leak tool that Ford uses, if you're only using a regular gauge fuel pressure is to be checked at wide open throttle. The calibrated leak/21 ft hose deal simulates wide open. Hope this helps.

Mdub707 · Sep 18, 2012

Never seen it that high with just the blue spring...

FWIW, I run my veggie pressure up around 85psi to make sure my diesel check valves stay seated, and no issues.

Andys04f350 · Sep 18, 2012

It is being measured at the port on the filter housing. I'm wondering if a regulated return will do this issue as I do not have one yet

Mdub707 · Sep 18, 2012

Well the idea behind the regulated return is that you can control what the pressure is. The spring really is a terrible way of controlling the pressure.

Big Angry Hillbilly · Sep 19, 2012

That's kind of what that spring does. It's a regulated return. Just before the injection side of the system. Plug the return side fuel line before the HFCM and fuel pressure will jump to around 100+psi and the pump howls like its going to fly to pieces.

My suggestion first off would be to measure pressure with another gauge to verify your gauge is reading correct. That does seem high for a stock system with only the blue spring.

That being said, higher pressure in that range is way better for the injection system than lower pressure especially in a HEUI engine.

Andys04f350 · Sep 19, 2012

No I'm thinking it may be the gauge/sending unit. My buddy is having the same problem I am and I ordered all the guages together. And he has a 7.3.

Big Angry Hillbilly · Sep 19, 2012

This is a gauge on your dash/pillar and not a gauge that's a tool for temporarily measuring pressure? I didn't catch that from the first post.

What breed is the gauge/sender?

I would definitely get a gauge on it. A tool one, not a permanent one and see what the pressure is.

Andys04f350 · Sep 20, 2012

Yes sorry. The gauge is a isspro ev2 on my pillar. I checked it with a tester and pressure is normal. So yes my gauge is messed up. Just random how two guages on two different trucks have the same problem.