Re: mystery valve=decel valve

[PDQSHIP@aol.com]

In a message dated 96-01-05 19:01:22 EST, you write:

>
>I too had the high idle problem. As Rod mentioned, I removed the "mystery
>valve", referred to by Audi as the decel valve. The decel valve is in place
>(only in the US versions, I've heard) to keep your engine from going 
>"Bum ba da bum bum da bum bum da bum" (everybody got that?) when you 
>take your foot off the gas and let the engine spin down. I guess Audi 
>thought people would object to this sound (I kinda like it). Put a nice
>loud free flowing exhaust system on and take out the decel valve. Then stand
>behind the car as you hve somebody rev the engine the let the gas pedal go.
>You'll hear that noise. I guess you could replace the decel valve with a
>functioning one if you really don't like the sound of the engine winding 
>down.

Well somewhat true, the decel valve will bypass the suction of the flap to
turbo inlet pipe, and equalizes the vacuum to atmoshpere in the air box. This
valve is triggered electronically by the idle switch function.......  Me, I
would leave it, after mucho debate with Ned and others, cuz what you avoid is
a surge rich fuel on snap throttle shut, on the 86-early 88 cars.....   As of
late 88 a bleed from the wastegate freq valve to a throttle shut delay makes
the valve redundant........  I debated the point for a while and concluded
that on a CIS car that is far from smart, this is a GOOD function, you could
get some serious engine farts with rich fuel, not a good thing.......  But
then that's what could make the German versions so much faster.....   Hmmmmmm

Scott