Stalling 10 valve 2CTQ Help!

[Blake Gibb]

We'll try this again. Thanks everyone who responded to my earlier
query. I just purchased a 1990 200 Quattro 10 valve, 187,000miles.
Car has had pretty religous dealer maintenence(for what that's
worth). When I come to a stop sometimes the car wants to stall,
normal idle seems to be around 8-900 rpm but occasionally it drops
down to 300+- and will stall if I don't catch it. That heel-toe
training I got at Bondurant 25 years ago still pays off. Looking at
earlier list postings I hoped it was the Turbo-Bypass Valve but I
have since learned that is only on the 20 valve. Any suggestions  for
the cause of my low idle speed and subsequent stalling would be much
appreciated. The idle adjuster was replaced about 10 months ago by
the dealer. One thing I have noticed-the temp guage creeps up about a
1/4" (just above the third red line at the beginning of the dial), it
does not get very warm. I had a non-qauttro 200 about 5 years ago and
as I recall it ran much warmer. I have only owned it for 3 days and
love/hate relationsgip is starting all over again. At least I knew
what I was getting into.
Thanks in advance for any help.
Blake Gibb