I cannot get my fuel pressure to stay constant. It is an 87 camaro 305 tpi. I have a new fuel pump, walbro. New fuel filter and a variable fuel pressure regulator, with a new diaphragm and spring. I cannot get my FP to stay constant, it jumps around from 40-50psi no matter how I adjust it varies. When I checked it I had the car running with the vacuum line on and off to try to get it to work. Please help
Thanks Shaun

 

I had the same problem. It's called a cheap *** fuel pressure gauge, just like the one that I bought from Autozone. Seriously, if you bought the $39 deal from them, then go exchange it, then that's probably what it is. Otherwise, you've got demons living in your fuel system.

JD

 

Thanks sIcK pUpPy
i thought of that and put the gauge on my trans am and it was reading perfictally.
Shaun

 

TTT

 

Well, the only other thing I can think of is a vaccume leak possibly. Silly question, but you are disconnecting your line before you test, correct?

JD

 

Yes i am disconnecting the vacum line. the only thing i can think of is it is either a bad fule pump or bad in jectors. which is odd because they are both new.
Shaun

 

Did you ever find the cause of the variation in fuel pressure guage??

Mine is doing the same. Previously checking it was constant with new pump. Been a while, and decided to check again...now it jumps.