Try disconnecting the bottom line on the big round actuator. I was having a similar issue, where I was only seeing 4psi max. Disconnect that line and I got 14+.Gents
I plan on tackling my boost problem (car isn't building any/or very little). 2006 SC, dealer purchase. You can see there is, I'm assuming, an aftermarket "T" (white) that is pushing a pressure signal (white line) to an aftermarket boost gauge. This white line is easily pulled from the brass fitting you see in the photo.
This may be the problem...or not. I've included pictures below to show the current routing of the vacuum lines in case that is a potential issue. I have a new boost solenoid and bypass valve ready to install. Any thoughts?
View attachment 31580
You'll find it sooner or later. Odds are its a very oddball case or something stupid. Hell, pull the charger off and see if the butterfly is even on there and functioning when you apply vac. This also gives you a chance to inspect the insides of the charger.I violated my own instincts and rule sets purchasing this car, bought sight unseen from a dealer out of state, and had it shipped here. I'm hoping it's not a complete lemon. My brother, who has built several cars, keeps telling me it's "all just parts and we'll find the solution eventually". Holding out for that.
Well, pull the codes first if you are getting the check engine light.You'll find it sooner or later. Odds are its a very oddball case or something stupid. Hell, pull the charger off and see if the butterfly is even on there and functioning when you apply vac. This also gives you a chance to inspect the insides of the charger.