One dead Audi. Any clues?

[Tom Nas <tnas@euronet.nl>]

Hi all,

I haven't used my car a lot lately, since I'm now able to commute by bike.
I've been using it for some shopping and a few short trips, but lately the
only 'use' was a trip to the car wash, next door. It started fine every
time I used it, and the battery's condition has never given any cause for
concern. It is however of an unknown age.

This morning I needed the car because I had an appointment after work, and
it wouldn't start. The lights on the dash just flickered, the rev counter
moved to 3k RPM, but the interior lights were still glowing brightly. There
was however a loudish groaning noise coming from the passenger side rear
wheel (opposite from the fuel pump). The central locking still works, but
very slowly.

I needed the car for the appointment anyway, so my neighbour helped me
tonight with his Opel and my jumper cables. It started instantly, and ran
beautifully until I came to my destination, and switched off. After that-
dead as a doornail. I'd noticed that while driving, the radio cut out
occasionally and the autocheck display would show 'OK' and 'ABS off'.
Hmmmm, electrical problem?
I could only drive back home by getting someone else's help with the jumper
cables agian. After that it ran perfectly once more, still occasionally
lighting up the dash.

So- the problem: car starts instantly and idles beautifully when
jump-started, displays 'OK' and 'ABS off' on the autocheck occasionally
when driving, dead after shutting the ignition off.

Does this ring any bells? What should I check- I'm not too much of a
mechanic, but I do have an excellent multimeter.

The car: (German spec) feb 1987 Audi 90 quattro B3/type 89, 2309cc NG
engine, aftermarket alarm/immobilizer (suspect?), ABS, heated seats, el.
mirrors but manual windows and no a/c.

I don't have a Bentley yet, but I suspect it will be of little use on this
strangely-equipped car anyway.

If anyone has BTDT, please let me know. I don't use the car a lot, but it's
nice to be at least able to use it.

Please cc: me on your replies, as I'm at least two weeks behind reading my
q-digests.

TIA!

Tom (relying heavily on my mountain bike)

 _______________________________________________________________________
 Tom Nas                                          Zeist, The Netherlands
 tnas@euronet.nl
 1987 Audi 90q 2.3E, Tizianrot metallic, 165,000km

       Don't worry about this. It isn't going to amount to anything.
                  -- Secretary of State Dean Rusk, during planning
                     of the Bay of Pigs invasion