fuel pump pressure

[racinrich]

has anyone actually measured fuel pump pressure? I know it is printed at 36.25 psi with no + or -. is the pressure regulator adjustable.how high is too high? fuel pressure that is ! my aftermarket pump installed by p o unknown mfg runs 39 psi constant all speeds and 2k old plugs are brown not tan or white,starts ok cold,runs ok hot.

[Rick G]

2.5 Bar is the official figure and that is 36 psi as you stated. Often the pressure will drop of slightly with age as the spring in the regulator loses tension but not increase in pressure.
The FPR is not adjustable but the pressure gauge you use to read it could be a bit inacurate. If you feel its not right check using another gauge and compare.
Make sure the rubber tube from throttle body #4 to the FPR is intact and not leaking as it can cause it to richen slightly if it is leaking (K100 & K75 only).
As long as the pump puts out the volume and it is capable of pumping 65 psi the FPR will regulate the pressure to 2.5Bar. It's the FPR that regulates the pressure at the injectors.
You can get adjustable FPRs but being in Australia I cant say where in US they would be available.
Firstly I would be making sure the gauge you are using is acurate.

[Scott_]

RR, personally I'd start by having the injectors cleaned. That way you are sure that they are able to be giving a nice even misting spray.
I haven't had mine done yet, but it is on my list for this winter once the snow flies.
My plugs also are a dark brown and my mileage is in the 30's local, and upper 40's on the highway.
It's also possible that the brown coloring could be from additives in the fuel that we get here in the mid-west.