Ok Peter, I think I did everything you said.
1) Checked the boost control hoses coming form the intake manifold to the switch over valve and the from the switch over valve to the ALDA. They were ok. No cracks or breaks visible. The rubber connectors looked ok too.
2) I checked the hollow bolt at the back of the manifold. It was clean. I checked the hollow bolt at the ALDA. It was packed with grime. I cleaned that out.
3) I checked the turbo. The wheel turns smoothly and freely.
4) I road tested it. The car still accelerated poorly.
5) I by passed the switch over valve to see if that might be the problem. Still no improvement.
I thought I had my problem solved when I discovered the crud build up in the hollow screw at the ALDA. There certainly was nothing happening with that bolt clogged the way it was.
What do you suggest I look for now.
Thank you for the help!
1985 300D w/ 196,000 miles