As title says, I hooked up pressure gauge, no leaks, started engine, reads 31PSI. Rev it some, the gauge goes to 33ish, then drops to 28 when revs dropping. New filter coming in 2 days, just trying to figure out if that doesn’t change anything, are these numbers acceptable?

From what I understand, acceptable range is 30-40PSI

 

Update: KOEO goes to 36-38 PSI, idles at 31 PSI once cranked, large revs will bump it to 38 tops. But it does still dip down fo 25-26 with some engine shudder, almost like engine is trying to recover after reving so that it doesn’t stall.

Replacement filter will be here Wednesday. In the mean time any insight would be awesome! I looked all over the forums for spec numbers but could only find 30-40 PSI on another website.

 

All looks normal

Unplug vacuum hose from FPR and plug the hose, then test again

Should stay up in the high 30's low 40's

When vacuum hose is attached to the FPR any high vacuum in the intake causes lower fuel pressure

When you REV engine vacuum goes down so pressure goes up
When you release throttle vacuum goes high so pressure goes down

Any "stable" pressure down to 15psi should allow engine to run fine.