If you go back to the 75-78 Bus engines you'll find a switch assembly on the
throttle body.
In one position it adjust for idle conditions and in the full open position
it gives the FI full electrical pulse. It is just the throttle body itself
that controls air flow by drawing it through the AFM at such velocity that
it opens the AFM flapper to the max position.

Stan Wilder
www.engineceramics.com
----- Original Message -----
From: "d spence" <dspence@OANET.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, August 05, 2004 8:18 AM
Subject: Re: vanagon Digest - 4 Aug 2004 - Special issue (#2004-716)

> It is probably intended to replace the function of the "accelerator
> pump" on carburated engines.  It shot a squirt of gas into the throttle
> area when you floored it to prevent stumbling from too lean a mixture.
> It provided fuel for the big gulp of air that entered with wide open
> throttle. As engine speed increased, so did throttle airflow, bernoule
> effect and gas flow through the jets.  Without the extra enrichment the
> engine would gasp on a lean mixture.
> On Wednesday, August 4, 2004, at 07:20  PM, Automatic digest processor
> wrote:
>
> > Date:    Wed, 4 Aug 2004 16:36:47 -0400
> > From:    Ken Lewis <kdlewis_wasting_time@ACCESS4LESS.NET>
> > Subject: Re: ECU and Throttle Question
> >
> > Here's my theory FWIW;  the thinking behind the activation of the full
> > throttle switch means you have "floor-boarded it" i.e. you need all
> > she's
> > got plus some. Looking at the O2 sensor monitor gadget (
> > http://neksiwel.20m.com/photo5.html ) on my dash the FI system has
> > stopped
> > toggling the mixture rich-lean-rich-lean and is now pegged in the rich
> > area.
> > How much richer I do not know.
> >
> > Ken