I received a number of replies concerning my earlier post. Some of
them were by people having similiar problems. So here is a list of
suggestions from the list and what I have done so far.
SUGGESTIONS:
- Replace the idle stabilizer (balck little elecrical box located
behind the right tail light) with one from the junk yard.
- Disconnect the idle throttle switch or lower idle RPM
- Replace O2 sensor:  BOS 11027     OXYGEN SENSOR  single wire
  $32.20   this one is a great universal replacement that's still
  Bosch if   yours is single wire.
  BOS 11929     OXYGEN SENSOR (OEM) $64.10 this is the stock OEM
  replacement.
  prices from www.fastgermanauto.com
- check the coolant sensor
- check the air flow meter
- go through the idle setting scenario in Bentley
- check all wiring in the engine area, see if anything is frayed or
   corroded
- check the throttle position switch for proper adjustment

WHAT I HAVE DONE:
- checked all the wiring
- checked the throttle switches (both click in the extreme positions)
- disconnect the idle position switch

Now the pulsing is gone, but my idle is way to high. I don't have a
tach but my guess is in the 1500 - 1700 range. Now there is no change
in idle speed between warmup and warm engine. Judging from that, is
my coolant temp sensor the problem?
I guess if the ECU doesn't get proper temp readings, it causes the
engine to run rich to compensate for supposedly cold outside
temperatures.

Cheers,
Marcus

58 Opel Olympia Rekord P CarAvan
59 Trabant 500
60 Opel Olympia Rekord P CarAvan
61 Opel Olympia Rekord PII 2-door
61 Trabant 600
74 Westfalia deluxe
79 Westfalia deluxe
84 Vanagon GL - daily driver