1.9 & 2.1 AFMS are substantially different and two entirely different
systems (even though they look alike on the outside).  1.9 Digijet and 2.1
Digifant sysrtems are the typical apple and orange, oil and water, etc.

If your 1.9 system in your 83.5-85 is intact, use the 1.9 AFM, Boot, etc.
For more info, see my 1.9 to 2.1 upgrade page:

http://www.oldvolkshome.com/19to21.htm

It's worked fine for me for the past 13 years.  The only major update is I
installed a European spec better performance  Digijet ECU 025906021F from
the late Boston Bob a few years back for smoother running and a little
better power, especially on the hills in a loaded Westy w/trailer.
--
Jim Thompson
84 GL 1.9 "Gloria"
84 Westfalia 2.1 "Ole Putt"
72 411 Station Wagon "Pug"
75 914 1.8 "Nancy"
Full Timing Since March 1999
oldvolkshome@gmail.com
http://www.oldvolkshome.com
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On Sun, Jul 25, 2010 at 9:57 AM, Evan Mac Donald <evanm@att.net> wrote:

> Aside from the physical difference of the inlet size at the rubber boot
> end, are
> there any real differences between these two items? If both complete sets
> (airbox, boot, etc.) were available, would a 2.1 AFM work with a 1.9 ECU?
> Just
> wondering, cuz I will be putting my 2.2 (up from 2.1) rebuild into a 1.9
> chassis...
>