I have searched and couldn't find anything that has been resolved. When I cold start my 87 stock turbo sometimes it will idle to 3 sometimes not. But the weird thing is that after the 3k, the idle sits at about 1200 rpm then slowly climbs until 2600. I was thinking bac valve but since it idles to 3k sometimes doesn't that mean it works? So now I'm thinking it is stuck open secondary butterflies. Anyone think that's what it is? Or could it be something else?

 

The car starting w/the 3k idle is dependent on temperature. If the coolant is too cold it should not start that way.

You have the BAC, the Air Bypass Valve and Air Supply Valve which all could possibly be players here. They are all connected electrically so you could unplug all three items and see if the same problem persists. Doing this should help to eliminate some possibilities.