Date:         Mon, 17 Sep 2007 07:06:37 -0400
Reply-To:     -------- <VW4X4@VERIZON.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         -------- <VW4X4@VERIZON.NET>
Subject:      Re: Internal Pictures of ECU's and ISCU's
Comments: To: tinker man <tinkerman007@GMAIL.COM>
In-Reply-To:  <1b0df96d0709162104w47881b4bh30e2da3d3ef0c63d@mail.gmail.com>
Content-type: text/plain; charset=ISO-8859-1; format=flowed

There is very good reason for these changes!  The reason is it did
not work very well, just like the surbaru engines.  Change is and
engineering way of admitting failure.  I've been running the
Golf/jetta digifant on an inline 4 cly.   This is a much smoother
fuel system with much better low end.   If I had the time I would
rip out the vanagon digifant system and try the  Golf/jetta digifant
system on a vanagon engine.   SOmeone years ago, in Canida
had an old mechanical  CIS fuel system on a boxer engine.....
                                                JOE w.




tinker man wrote:

>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...:-)
>
>
>
>