[T3] Weird Idle Dips, Suggestions?

[jadney at vwtype3.org (Jim Adney)]

On 23 Feb 2012 at 16:47, Toadpipe wrote:

> For several years now my 69 square does the strangest thing when idling 
> for about the first five or so minutes after starting up then runs 
> normally.  It revs up to idle then down to near stall then right back up 
> with about one second between the peaks.  Does this only while idling, 
> runs normal if I touch the throttle at all.  What could fix this?  Is it 
> a sensor issue or something?  I can't seem to figure it out, but the up 
> side is it doesn't seem to be a huge issue, it's just annoyed me for far 
> too long to allow it to continue.

It's most likely that your idle speed is set just a bit too high. 
What you're describing is the loping behavior that's common if the 
any time the idle speed gets too high. The problem goes away when the 
engine warms up and the aux. air regulator (AAR) closes. 

Your description indicates that the AAR is working properly.

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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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