Date:         Fri, 7 Feb 2020 10:25:18 -0800
Reply-To:     Neil N <musomuso@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Neil N <musomuso@GMAIL.COM>
Subject:      Re: Vanagon Syndrome/AFM Mounting Orientation?
Comments: To: alex@mevay.org
In-Reply-To:  <CACARJKqQA51VxjJMCowFAYkgrAmeUagAPp=3jaP-eHTB7Uk63A@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"

I'm not a Digifant pro have included words such as "likely" so take
this for what it's worth LOL  but descriptions of engine management
systems here:

http://www.a2resource.com/electrical/management.html

vs a description of Motronic for Mk3 VW's in my Bentley manual which
makes specific mention of Motronics' "adaptive" aspects, likely
suggest that Digifant II is not adaptive. e.g. unlike Motronic,
Digifant is not able to compensate for things like minor vacuum leaks
due to normal wear at throttle body. e.g. Motronic and newer versions
likely have subtle control over the ISV or motorized throttle body
(OBD2) so either can compensate for minor differences in air to fuel
at idle.

IOW Digifant is likely not designed to "learn" or adapt to a given AFM.

The AFM CO adjustment likely only really affects things at idle. As
I'm sure you know, it's an air bypass within the AFM designed to be
used at idle when the vane is mostly closed. IOW, with the throttle
part way open, thus AFM van part way open, most or all air is passing
through the main part of the AFM.

Neil.

On 2/7/20, Alex MeVay <alex@mevay.org> wrote:

> Two bonus questions for any Digifant II pros:

> 2. Does Digifant II have any long-term learning/adaptation to the fuel
> map?  When I replaced the AFM in 2018 and did the idle CO as above,
> the engine first ran a little rough (i.e, blip the throttle for a
> shift and get a misfire), but then got smooth over the next few days
> or so.



-- 
Neil n

VE7TBN

1988 Westy 50º ABA swap: https://tinyurl.com/yap5hpwt

1981 Westy 15º ABA swap: https://tinyurl.com/y9n4xob8

VAG Gas Engine Swap Group <http://tinyurl.com/khalbay>