i've been having this problem for a while, but when i set my boost controller to 16psi it sometimes hold and sometimes doesnt? it will hit to 16psi then drop straight down to 8psi like what happens when the det sensor retards the timing and drops the boost? both the factory solenoids been disconnected so what do you guys reckon? ive got a greddy profect A cont. i dont reckon its a vacume leak cause sometimes it holds boost esp. when eng. has been running hard for a while? cheers!:YD
Probably controller From what you say the solenoids are disconnected so the ECU cant drop the boost. It can still failover to the knock fuel and ignition maps though. But since the profec is in sole control of the boost thats where i'd start looking. If its a pnumatic controller (I've never seen inside a profec) then it works by bleeding air from the wastegate signal line. If something is blocking this bleed off then all you'll get is stock boost. Say theres a bit of crap in there blocking it occasionally then clearing, that might give the symtoms youre describing.
