Thread: Fuel pressure problem?

I dont know for sure if I have a problem or not but, last summer I had a baseline dyno run and I tuned my fuel pressure when I did the run. In the heat of summer I needed to run 32.2 psi of fuel pressure at idle 40.5 with the hose off to get the most power, it was at least 100*F outside that day. Today I noticed my fuel pressure was abnormally high 38-39 psi at idle and 48 psi with the hose off! But it was about 60*F when I checked it today. So whats the deal is it working right?

I suspect maybe there's more air pressure or something when the air is cold making my fuel pressure setting get messed up? But then if I put the fuel pressure back to stock (36psi hose on 43.5psi hose off) how do I know its not running it lean? Could a malfunctioning fuel pump cause this?

I'm using a NISMO FPR by the way.

EGT GAUGE and measuring cfms always helps when you dont have a dyno at home.

Or a wideband.