Rough idle on '82 CGT

[Huw Powell]

Geordie wrote:
> 
> OK, I've been trying to figure out what to fix, but I just don't know.
> 
> When I fire up my '82 Coupe from a cold start, the engine idle speed is very
> low. It just hovers around 500-750 RPM or so. It does not automatically turn
> on to a fast idle and warm itself up. I have to put my foot on the throttle
> to keep the idle speed up until warm. When the engine is warm, it idles at
> the perfect RPM.

the cold engine enrichment and idle speeds are "controlled" by two
devices that warm up with the engine (they are both heated electrically
but the WUR is bolted right to the block as well)

Anyway, the Warm Up Regulator does the enrichment, which probably is not
your problem, but it can be cleaned a bit by removing the two fuel lines
and blowing out the screens - very carefully, you're playing with fuel.

The more likely culprit is the Auxiliary Air Valve, bolted tot he rear
of the intake manifold.  This device is an air valve that bypasses the
throttle body and is wide open when cold, closes as it warms up.  Follow
the "vacuum" lines to find it.  I have no pix but I do have two in the
attic.  If it is sticking or jammed or clogged, the engine will not get
enough air to idle properly when cold - which you fix by cracking the
throttle.

-- 
Huw Powell

http://www.humanspeakers.com

http://www.humanthoughts.org