UrQ Low Boost - Update

[Andrew Finney <afinney@tamsconsultants.com>]

In the never ending quest to figure out why my 1983 TAP'd UrQ
only makes 8psi gauge of boost, I removed the wastegate heat
shield. What I found was that one of the bolts that holds the
wastegate to the exhaust manifold was missing, and there was
evidence of exhaust having escaped between the wastegate
and manifold. I did a little dance, in celebration of an easy fix.
The Audi Gods (TM) saw my dance and removed my joy. Still,
8psig. 

Hypothesis - I have checked the hoses and turbo, all seem
OK. Could the exhaust leaking past the wastegate have coked
up the valve, or overheated it causing it to stick? I remember
hearing once that if exhaust can escape to atmosphere it will
heat the affected part to a higher temp that if it continues in a
closed system out of the tailpipe. Does that make any sense?
Isn't that why air injection emissions system work, to continue
the reaction? Anyway. It still looks like wastegate problems.
The bolt has been missing a long time as evidenced from the
rust in the seating area of the missing bolt. Is there a gasket
between the wastegate and manifold that could have burned
out? Should I check anything else first, or is it time to pull the
wastegate, arrgghhh.

Thanks for any and all input. Thanks to all who have made
suggestions.

Andrew Finney
1983 UrQ.