Idle's one thing -- that's the responsibility of the idle speed controller
dingus, pretty much.

But when the engine is being spun by outside forces (say, downhill in
gear), then foot off gas = zero fuel. It's in the Bentley's somewhere.
Manual's not at hand but I did look at that and post it here late 2007,
early 2008.

TI think that there is at least one throttle body switch + rpm condition
not well explained in the Bentley's manual. List members hand-waved that
off by saying that the ECU sees the Hall sensor and does some ju-ju with
the data. But we don't like black boxes.

--
Mike "Rocket J Squirrel" Elliott
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
Bend, OR
KG6RCR

On 8/17/2009 1:52 PM pdooley wrote:

> Hmmm, I may have an answer for my own question.
> The hall sender could detect RPM below or approaching idle speed and add
> fuel.
>
>
> -----Original Message-----
> From: pdooley [mailto:psdooley@verizon.net]
> Sent: Monday, August 17, 2009 4:45 PM
> To: 'Rocket J Squirrel'; 'vanagon@GERRY.VANAGON.COM'
> Subject: RE: Not quite a backfire . . .
>
> How does this work?
> How does the ECU know to shut fuel completely off when descending but yet
> could add fuel in a split second to prevent stalling if say, you press the
> clutch pedal in?
> The idle switch cannot discern the difference between idling and coasting in
> gear.
> I really don't see how the AFM could perform this function either.
> Somebody enlighten me.
>
>
> <With no pressure on the gas pedal, the fuel is totally shut off, so the
> engine is not firing on any cylinders.....
>
>