Novice + Boost issue = ?No Hope?

[ALPHA1220 at aol.com]

Here is my situation, maybe some more experienced people can help, since my
moderate level of knowledge concerning car mechanics hasn't gotten me very
far. I have been driving a 1991 200 20v quattro for approximately 9 months,
having taken it out of storage (My Dad drove it from 1991-1995). For as long
as I have been driving the car, I have never gotten maximum boost: 1.4 was as

high as I was getting in the summer and fall of 01', 1.3 in the winter and
spring, now down to 1.2. When I first began driving the car, I noticed what I

thought was an issue with finicky clutch engagement: coming to a stop
following hard acceleration would often cause my car to stall (an embarassing

thing). I just blamed it on being lazy and not fully engaging the clutch.
However, even with my extra "caution" I have noticed that the car will still
stall occasionally -- always under the same conditions of hard acceleration
then coming to a stop. In the spring, I had my Dad take it to the Audi
dealer. They took it for the whole day, drove it around, charged my Dad like
$300 and told him nothing was wrong with it. (I assume they focused mainly on

the stalling issue, ignoring the boost problem since they had no idea what
the hell they were working with and probably just pulled up the specs for a
200 10v and assumed I was getting max boost).

So my question is twofold:

1. What is most likely wrong with my car, and how do I confirm it?
2. What do I need to do to fix it and return my car to a normal op. specs.
(If possible, I'd like to do it on my own, so anyone who can give me specific

instructions, please do so. If not, tell me how to find a reputable place to
get my car fixed).

Sorry about the long and complex question. I'm grateful for all responses.

Alpha1220 at aol.com
Chicago, IL