Audi 4000csq problems -- help!

["Hamilton, Peter F" <peter.f.hamilton@lmco.com>]

Folks,

My trusty 1986 4000cs quattro has let me down!  It's got ~150k miles on
it, and has had some modifications, i.e. 30 thou off the head, extrude
honed intake, performance exhaust, shocks, etc.  Anyway, here's the
story:

1. Friday afternoon.  Notice a "buzzer" sound that happens when key on,
car not started.  Oil light on during buzz.  Check oil, it's fine, car
runs fine.

2. Friday night the dashboard started acting up.  Tach dropping to zero,
back again, radio cutting on and off.  Weird.

3. Figured it was a short in the dash, pulled it off to mess around with
it.  Thought it might be a relay flipping out, tried pulling relays, no
luck.  No fuses blown either.

4. Frustrated, try to start car for hell of it.  Battery dead, won't
turn over.  Really weird.  

5. Jump start, fires up fine, poke around again.  Pull another relay
that I thought was buzzing.  Nothing happens, replace.  

6. Turn off car, restart.  Runs for ~3 seconds, then dies (sounds like
it's running out of gas)

7. Repeat ad nauseum.  Add gas to tank, repeat again

8. Swap battery with fresh one from friend's car.  No change.  

So... anyone got a clue out there???  Did I kill it by pulling a relay,
or perhaps fry something by running it at a low voltage with an almost
dead battery?

Any help would be appreciated.  I'm about to have it towed to a dealer,
which I *hate* doing...

thanks,
-Pete
Peter Hamilton
(607) 770-4196
Mechanical Engineer
Peter.F.Hamilton@lmco.com
Lockheed Martin Control Systems -- Hybrid Electric Vehicle Development