From: Peter Florance
Date: Sun, 3 Jun 2001
Subject: RE: A/C 134a Conversion

The ac compensation valve routes a little air around the throttle plate (on
Ljet cars) to boost the idle during AC operation. It's on the intake plenum
near the rear with 2 wires. Only 80 and 81 cars had them I believe.
Might work on a carb. It of course depends on a port being present on the
other side of the throttle plate but above the venturi area (so it didn't
act like a vacuum leak). This is all hypothetical as I don't know if such a
place exists. And I'm a little fuzzy on how carbs work but I think I have
 Probably the better way to do this is to use a vacuum valve off 530i
(powered by compressor +12V) combined with your throttle vacuum solenoid.
Hey if it doesn't work any more disconnect it. But it might.
My 70 Tempest had some sort of solenoid that was enegized anytime the key
was on. Theory was when you turned the key off, the throttle closed below
idle so it wouldn't diesel.

-----Original Message-----
From:	Bruce Farrar []
Sent:	Saturday, June 02, 2001 8:40 PM
To:	Peter Florance
Subject:	RE: A/C 134a Conversion


I'm not aware of this device, but can you explain it more to me?  My a/c
tech said that there is a GM dc powered switch used to boost the idle
a/c operations of some post 1980 chevys and buicks, but he didn't know
exactly what part, etc.  My Bav had a vacuum operated daspot that was
continuously held retracted until some vacuum was applied within the old
smog stuff allowing it to extend thus increasing the throttle position
somewhat and I could probably use it, but am leary of relying on a 27 year
old vacuum valve's longevity.


  I've got a dumb question about carbs and AC - do carbs have a decent
port below the throttle plate? If so maybe e12 type AC compensation valve
could be used to regulate idle a little better....
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