Hello again,

In this never ending saga of analyzing the various versions of ECU's
and Idle Stabilization Control Units (ISCU) used in our vans, it seems
there was a great variety indeed!

ECU's:
1. My 1990 Euro-spec Digijet uses a 8049H microprocessor (uP).
2. David Kao reports his 1984 US Digijet ECU uses a Z80 (Zilog) uP.
3. Jon Kenneke reports his Digifant uses a 6803 uP.

I find it quite amazing that VW implemented the same basic technology
(digifant/digijet) with at least 3 uP familes!! What a nightmare to
manage and update!

Likewise, there were many ISCU versions:

At least 4 models of ISCU's for 1986-1991 vanagons:
251 907 393A Earlier European models
251 907 393B Earlier US models
251 907 393C Later European models
251 907 393D Earlier US models

All worked with an additional external ICV (Idle Control Valve).

A completely different design (no ICV) was used  for the 1983.5-1985
ISCU's that I have no part numbers for.

I think it would be beneficial that anyone who has good-quality images
of ECU or ISCU internals add them to the VanagonWiki site in the
appropriate place and/or forward them to me for further analysis.
I suggest each include model year and country, Part number, and at
least one good image.
Let's see where this takes us (except for overflowing my mailbox...:-)