hey ht, my ef sedan has been driving me crazy for a couple days now. last week i checked my fuel pressure and it was 55 psi with or with out vacuum about 10 psi to high. i figured the fuel pressure reg was bad so i ordered a b&m adjustable reg and guage and got a new regulator. last night i installed the new reg with b&m adjuster and guage. with the engine off the fuel psi can be adjusted to whatever,with no problem but with the engine running fuel psi cannot be adjusted it stays around 52 -60 psi. the car has a stock fuel system other than the b&m s**t.
if i turn the regulator to the lowest setting the car runs like crap,like it has low fuel psi but the gauge still says 52 psi!!!!! it seems like the gauge is bad but why does it work ok when the car is off??? any GOOD ideas?

 

bump

 

sounds like a blocked return line to me buddy!

 

Pull the fuel pump fuse and try and start the car. What does the guage read now?

 

0. im thinking it might be that valve thing that connects the fuel line from the filter to the rail. does anyone know the function of that thing?

 

bump

 

The round looking thing on the end of the fuel rail? About the size of a half dollar? Has a little plastic cover on it? Thats the dampener. It helps reduce fuel pump oscillations and keeps constant pressure at the rail...
Have you checked the return line for blockage?

 

yeah thats it. that part can go bad right? and yeah i checked the return and it has no restriction

 

Is your guage on the fuel filter? Or on the end of the fuel rail? Got a pic?
I think if it were bad, it would not cause driveability problems. I see people all the time on here that dont even run that dampener.

Nothing else has changed? Wait a minute, just thought of something. The B&M is just the top hat portion correct? Utilizing the factory lower "regulator" portion?

 

yeah b&m regulator modifier, im almost positive its the damper now dude, i took it off poked the inside with a screwdriver and put it back on and now the gauge shows proper fuel pressure adjustment changes, i forgot to mention there was a driveablity prob. the car would fall on its face after 5200 rpm now after messing with the damper it rips all the way to 7 grand but now bogs at lower rpm

 

Looks like you found your problem!
Im trying to understand how the damper is going to affect pressure. The restriction(regulator) is on the end of the rail which controls pressure.And the pump output is still the same, so how does the dampener affect the pressure? Sticking open OR closed shouldnt effect pressure.
The guage is on the filter I assume? Perhaps someone else has an opinion.