A friend (another local VW nut) brought over a Bosch 022 "D" version of
the 2.1L ECU today. (Bosch Part Number: 261 200 284/285) Of course, we
pulled the thing apart.

As most folks know, there are at least three versions of the ECUs used in
US 2.1L Vanagons:

Triumph Adler 022 (is there a TA 022 "D" version?)
Bosch 022
Bosch 022 D

The Bosch 022 "D" version is MUCH different than the TA 022 unit. The
analog component count is far fewer, and uses more modern design
techniques (ie some surface mount components).

I've always heard the "D" version is better, but besides having more
modern construction, what is the scoop?

I haven't pulled the thing apart enough to get part numbers, but that will
be coming.

Jon (The AFM guy)