Rough Idle - 91 LTC

[Borman]

I've got engine rough idling, though not stalling, at hot engine and at Drive position, when I stay in traffic jams, at traffic lights etc.
There is no rough idle while in Neutral at any times.

What can be the cause?

Idle Control Valve is new, just replaced couple weeks ago.

 

[formerknown]

Check your Mass airflow sensor. Remove the sensor with torx bits and clean with spray electrical cleaner. Disconnect the battery for 30 minutes, reconnect, then start her up...