1988 745 TIC.
Garrett TC

Earlier today i took her out of storage, fired up, changed oil after an hour etc.

Car ran spectauclarly for about 20 minutes, then i stopped for lunch, fueled up and left. About 10 minutes into the ride i left the light, hit the gas and at about 3/4 throttle it hit 3000 rpm and then dropped like i hit a wall. did this several times, went right up on the boost and just as it would normally start pulling hard it would drop @ 3k rpm and then go back.

I stopped at my garage, checked each and every hose/vaccum line and fitting for tightness, all were excellent.

Took off from a light again, this time at 3500 rpm starts making a loud WHOOSHING noise, and the turbo was working (could hear it spooling) just as the turbo would start to make power a loud whoosh (almost like bleeding a compressor tank) would eminate from the pass side (around the turbo area) the boost gauge would just sit at the 12:00 o'clock position with the car sounding like a huge vacuum cleaner, no boost and insane amounts of black smoke from the tailpipe. I ended up going back to my garage and pulled the intercooler completely out to make sure it was fine. (it was) all hoses were fine, and the only notable one i replaced was the small hose from the turbo output to the wastegate.

I asked the question on turbo bricks, i got a few answers, exhaust manifold bolts (they are tight) hoses (yup, they are fine) and the CBV (compressor blowoff valve)

Anyone ever eperience this, the car is literally not driveable. what are the sypmtoms of a bad CBV, and tips tricks hints appreciated!!

Thanks

Chris