fuel pressure regulator problem

[btimby]

hey i got a 91 explorer and today i was running some fuel pressure tests off the bleeder and i had some strange symptoms...it ran at the right pressure (38 psi, specs say 30-40 psi) at idle, but when i went to test vacuum by punching it, it shot up to 90+ psi and wouldnt come back down. im guessing its the diaphragm in my fuel pressure regulator and will need to be replaced...anyone come across this before? any other possibilities?

 

[410Fortune]

Not many 91 explorer's are still on the road with the original fuel pressure regulator, yes it has been run into before.

Any raw gas in the vacuum line to the FPR?

 

[MrShorty]

Haven't heard of that exact scenario before.

About the only other possible cause I can think of for such high fuel pressures would be a restriction/clog/pinch in the fuel return line to the fuel tank.

 

[ExplorerDMB]

do NOT double post please. I merged this thread and your other together. Thanks

-Drew