89 Bonneville-Cold Air Idle Control?

[twisted89le]

Hey guys...having a problem with it periodically idling rough and popping thru the exhaust during some cold mornings.. also when I turn on the defroster option.........i'm thinking its something to do with a vacuum solenoid or idle control somewhere.....it mainly does this on frosty mornings or around freezing......but runs fine after it gets heat in the motor....any ideas?..

Thanks,
Matt

[SSEBonne4evr]

There is an idle air motor under the throttle body.\
Probably gunked up. I have one for sale if you need it.

[MattStrike]

It could also be an ignition issue (plugs, wires, coils) or a bad intake temp sensor, possibly dirty mass airflow sensor. It should idle higher when it's cold, and slowly drop in speed as it warms up.