Adjusted FP but have a ?

ram360

Founding Member
Oct 19, 2002
2,162
1
59
Pennsylvania
I adjusted the fp from 39 to 42 psi. I pulled the vacuum from the fp regulator and plugged the port on the intake where it was connected. I adjusted the FP to 42 then unplugged the port and reconnected the vacuum line to the fp regulator. With the vacuum line hooked up the fp only reads in the low 30's w/ the vacuum line connected and 42 when the line is disconnected the the port is plugged. Is this normal or am I missing something? :shrug: Might be a dumb question.
 
Agreed. anything over 30 PSI with the vac line on is acceptable, though your range is a little high.

Good luck.
 
luckythirteen13 said:
thats normal. the reason you unplug the vacuum line when settin fuel pressure is to simulate WOT conditions. when you hook up the vacuum line, the reg. knows your not at WOT and cuts the fuel pressure down
Yes, but the static range between vac-line attached and vac line plugged is supposed to be somewhat fixed - if WOT pressure goes up, so should idle pressure. That is the strange part here.