Holley Blue was idling at 12.5 yesterday, now all of a sudden it's idling at 14 !? ...what would cause the pressure to rise...{mechanical isspro gauge with snubber valve on it}...about the same cruising PSI 9-10..

 

Pressure regulator in the pump getting dirty I'd assume. Take it out and clean it. (the one big screw on the pump case, there's a spring in there and a piston)

HTH

AlpineRAM

 

if the snubber is adjusted to tight it will peak and hold. might want to check it

 

Check connections positive and ground,also a heavy electrical load could be turning on and of such as A/C.Merv