Engine/Transmission (1994 - 1998) fuel pressure bleed off

[johnls]

I got another question for all of you with fuel pressure guages. I got my guages installed and noticed the fuel pressure was reading 18 at idle and then when driving would drop to about 10. So I looked on the site and found out to stretch the overflow valve spring. Now I am running about 28 at idle and about 40 driving so I am going to replace the OF valve. Now my question is when I shut the truck off the guage immediately goes to zero. Is this normal or will the OF valve fix that? Also I have the shutoff valve on the fuel pressure just barely open and you can here the guage making noise in the cab, kind of like the ticking you can here from under the hood. It is an Isspro guage. Is this normal also? Thanks

John

 

[johnls]

Okay I have the overflow valve replaced and my idle is 22 psi and my 2400 rpm is about 30-34 psi. Now my only thing is that as soon as I shut the truck down the fuel pressure drops to zero in about 2-3 seconds. Should it hold pressure for a while or is this normal? Anybody with a FP guage please let me know what yours does. Thanks

 

[EKlem]

Mine took about 30 seconds to bleed down before I put the snubber in and now it takes like 2 minutes. We had a fuel pressure gauge on on of the buses here(dt466) and it would stay pressured for 15 or more minutes. Sounds like you have a pinhole leak somewhere.



If you aren't having trouble starting the truck, it doesn't seem like a big deal to me. If I am wrong on this, I hope someone will chime in and say so but I can't see a problem unless you are introducing air into the lines.

 

[johnls]

Anyone else have a fuel pressure guage? If so does yours drop quick on shutdown?

 

[WDixon27]

mine zeros in a few seconds with a new lift pump and home brewed pieced together of valve (half dodge/half mercedes but it works), a snubber just keeps pressure in the fp gauge longer, close the valve a little more and the ticking in the gauge should stop, i have mine at the point where i can still just barely see the gauge move with the pulses at idle but the noise is gone

 

[12V Ford]

Mine drops within a few seconds also and so does my brother's and he has a new ov, lp, and fuel lines.