Testing fuel pressure regulator
Thread Starter
Instructor
Joined: Nov 2007
Posts: 108
Likes: 0
From: Waukesha WI
Testing fuel pressure regulator
Might have a bad regulator, was told to take the return line off of the fuel pump assembly and clamp it off. Then put a fuel pressure gauge on the schrader valve on the fuel rail and test fuel pressure. If it doesn't maintain pressure then regulator is bad. Is this true? Also, if this is true do i replace the regulator, diaphram and spring, or both?
Melting Slicks
Joined: Oct 2006
Posts: 2,314
Likes: 3
From: In a van down by the river! Florida
put a gauge on the schrader valve, check pressure with the rails primed, engine off, engine on with vacuum attached, engine on with vacuum off.
Smell the vacuum line, see if it has any fuel in it.
If you see more than 43psi your reg is bad
Smell the vacuum line, see if it has any fuel in it.
If you see more than 43psi your reg is bad
Thread Starter
Instructor
Joined: Nov 2007
Posts: 108
Likes: 0
From: Waukesha WI
Right now the problem that i'm having is a lean condition, like there isn't enough fuel pressure, not too much. What vaccum line do i disconnect?
Team Owner
Joined: Jul 2004
Posts: 28,418
Likes: 3,273
From: Hartford WI
You want to disconnect the one leading to the FPR. That gives the FPR a "WOT" vacuum signal so you know what the max pressure is.
