Re: typ44TQ: rpm's kick up whenever climate control turned on?

[ti@amb.org (Ti Kan)]

JordanVw@aol.com writes:
> on my '86 5kTQ, whenever i turn on the climate control (both heater or the 
> a/c affects this) the rpm's kick way up, and only go back down to normal when 
> i shut off the climate control.  its more apparent when idling in neutral.
> 
> normal rad. fan temp operation doesnt affect this, it just happens when i 
> turn on the a/c or heater.

There is an air valve that opens to increase your idle speed slightly when
the A/C compressor runs.  The purpose is to counteract the idle speed
drop that would occur due to the compressor's load on the engine.  The
A/C compressor also runs when the climate control is set to defrost, even
if the temperature is set high.

The action of the valve should be subtle, though.  It should not cause
an increase of more than 200rpms or so.

-Ti
96 A4 2.8 quattro
84 5000S 2.1 turbo
80 4000 2.0
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