CIS idle hunt problem found
 

My car has had the dreaded idle hunt since the weather went cold last fall. Also, the car has been dying when the engine settles back to idle. I've been jacking with the decel valve some since the prob started with very little result. Tonight I started the car and pulled the vac line off the decel and the idle immediately went stable. I searched the archives and found a thread where where John Walker suggested that the mixture may be set too rich. Creating the vac leak leans the engine, smoothing the idle. It also is tending to stay lit when it settles to idle now. Just need to tweak the CO a bit now.

Thanks again JW.

Sweet! I hate CIS gremlins.

My SC wavers a little when I first start it on a cold day. It soon settles down once I get going though - and never stalls.

Is there anything to worry about?

mark, you should plug the hose. creating an intake air leak is not an alternative to leaning the mixture.

Understood. Just didn't have the right allen wrench last night to adjust the mixture. I'll take care of that tonight. Thanks again John.

Dumb question, but does anyone know, on a 930 ( 1986 ) is there a mixture adjustment point that utilizes the allen wrench mentioned many times on this board? I must be blind, for I cannot seem to find it, if such an adjustment exists.

the 930 adjuster is hidden next the curl of the air filter housing, to the right of the two bolts that hold the housing to the sensor plate housing. you can see the top of it about level with the top of the air filter housing. it's spring loaded. you stick a 3mm allen wrench (longish) in it, push down to engage the lower, inner adjustment screw, and turn CW for rich, CCW for lean. air pump hose must be clamped shut and oxy sensor unplugged if you use a gas machine.