i have a fuel pressure gauge and i know it's been working. i went to set a lower static pressure and i adjusted the screw on the regulator and all the way in or all the way out, the gauge reads about 42. i have a vortech standard (non-adjust) fmu and i remember before i put it on there, i could adjust the pressure from the regulator and when i revved the motor the needle would rise on the gauge. since the fmu install, the gauge just reads 42 and when the motor is revved, the needle doesn't rise. i am pretty sure it is hooked up right or does this just happen when using an fmu because there is a set static pressure? i thought fmu's could be used in series with regulators though...i need some input and peace of mind.

 

Gauge is probably busted. You cant really run a gauge with a high rate FMU.
They cant take the high presure and just break.

 

what fuel pump are you using? were is it plumbed in and were is the gauge?

k

 

yes there should be a rise in fuel pressure when you rev the engine, even if you dont go into boost. I assume that you still have the stock fpr. If not, then that is your problem. The stock(or aftermarket) fpr on the fuel rail should handle the fuel pressure when the engine is operating in vaccuum. It sounds like you may have set you static fuel pressure (with the vac hose DISconnected) to 42 psi. Your idle fuel pressure will also be at 42 psi or so since it will not go below this with the stock fpr unless you drill a hole in it.

So what may be happening is that your idle fp and static fp are the same, and as such there is no rising under vaccuum.

ps. If what i said about the idle FP is not true then this is mostly wrong. I personally tried to lower the idle fp on my car with a B&M Commandflo ont he stock fpr and it would NOT go below 41-42 psi. Your results may vary.