Advanced question about fuel pressure flucations

[articzap]

My car can never seem to hold a constant pressure.

ex. I start it up and drive it at 45 psi. Turn it off and go something. Come back it'll be at 42 psi. I got fill up the tank and it'll go to 50 psi. Let it sit for a few days and it'll go to 55 psi.

I'm trying to decide if it's my fuel pressure regulator if there is a nick on the rubber line going from the pump up to the top of cover. There are no present fuel leaks that are visible. I just don't want to buy a new FPR and have it not solve the problem.

Thoughts and opinions please.

[rico05]

Stock FPR? What is your fuel tank venting setup like?

Stock FPRs like to die. Just a heads up. My Nismo holds rock solid and I have the vent open.

[articzap]

Open vent. Walbro 255 lph. Synapse FPR.