This morning on the way to work my fuel pressure was going all over the place. With slow acceleration or just kinda crusing around 1500 rpms or so, it would drop or raise with no real pattern. Sometimes itd be at 36, sometimes at 38, and sometimes it would drop real quickly to like 23-29 then slowly come back up. but sometimes it would come back fast. Does this sound like it could be a problem with the fuel pump or could it be the regulator acting funny? It is an aeromotive boost referencing for the lt1 fyi.

 

Might be easier to diagnose the problem if you had a real mods list in your signature.

 

hahaha I know, ill get to it eventually. Im running the walbro 255 with hotwire kit. prob has 2k miles on it. I am using the bucket still. Stock fuel lines, stock rails, mototron 60 lb injectors, aeromotive boost ref FPR. VRE 355 with Vortech T-trim

 

Experiencing any drivability issues?
Electric pressure gage?

 

Was this jumping around happening while maintaining a steady throttle?

 

did you check the pressure at the line to compare it to the gauge?
fuel pressure regulators are simple devices, they're either good, bad, or leaking which is generally bad

 

Yeah I was going to ask if you verified the gauge's accuracy, that is the first thing I would do. If there were drivability issues directly associated with the readings I would take that as some level of proof of a problem with something other than the gauge.

 

Well the problem seems to have gone away. It didnt do it at all after I posted yesterday. I should make a post about optis, clutches, and 10 bolts just to keep myself safe

 

well i think i solved it, i think the electronic sender may have been getting interference from my air/water intercooler since theyre touching somewhat

 

damnit, its still doing it, today it was dropping to like 9psi-21 psi...would a car even be drivable at 9 psi because i couldnt really tell a difference in how it was reacting

 

Umm...No.

 

so what range should it technically be driveable on? i dont have a manual gauge handy to check. Im assuming its electrical related as it will drop from 38-20 then go right back up to 32in a matter of maybe a second or so. it also has no real pattern but never goes above 40, which is the highest it would go where its currently set at anyways

 

Where is your electonic pressure sensor located? Subject to engine vibrations? Is your gauge a digital or analog?

With regard to what pressure it should be at, its difficult to say without knowing what your tuner assumed or was told the fuel pressure would be when he did the tune. Normally, I would think he would assume (unless told otherwise) that it was at stock fuel pressure - 43.5psi - with no vacuum or boost compensation. Is your vacuum/boost gauge moving in synch with the fuel pressure gage?

 

It is kinda jammed right behind the vortech aftercooler, which is wrapped in heat sheild which im thinking may be causing interference. It is set to 43.5 with no vacuum. it hangs out right around 37-39 with vacuum reference and will go to 43 right before boost usually. Now there is no real correlation to the readings and revs

 

With no drivability problems and readings that low I would strongly suspect the gauge/sender.