I noticed today that my FP is dropping during my shifts and seems to be running a little low from what i've noticed normally. It's running about 34psi while cruising, upps to about 36 to 38psi when accelerating but drops to 30psi on the shifts. 6spd with a Racetronix 255 in tank and direct wire setup by the way. I just don't recall it ever being like that before. As for pressure regulator goes, it's a TPiS adjustable and i've had it for about 80k miles and about 9 years. Any ideas? Thanks.

Ken R.

 

Are you letting off the gas during shifts? If you let off the gas you create vacuum in the intake which will lower your fuel pressure until you go back wide open.

 

Exactly like Markinkc69 stated. What you need to be concerned about is if your fuel pressure starts dropping at WOT as your rpms rise to your shift point.