After removing and re-installing my UIM for polishing/painting and removing the double throttle I am having a problem when boosting into the secondary turbo. It seems to not want to transition at all. It boosts perfect on the primary turbo at 10 psi but at 4500 rpm it falls off to about 5 psi and makes a funny noise. I'm not real sure what to check. On the vacuum diagram... the switching solenoid, is that the solenoid which controls the switching of the turbos or what? I can't imagine that it would be anything too serious.... Couldn't be a cracked turbo housing right?

 

Check your turbo control solenoid on the ACV. It you popped off a line on that sucker or somehow disconected it then that is the problem.

 

I think i found it, thanks. There seems to be a hose off of a nipple under my UIM