When starting my 2.2 when its cold it will idle very low. If you rev it up it and let it off it will drop down really low and then recover to a low idle and sometimes it will drop so low it stalls. Once it warms up it seems to be OK but idles low enough that the headlights dim. What is the proper idle speed for this engine.

 

Check the ECU coolant temp sensor. This sensor tells the computer if the coolant has heated up to a certain temp. The ECU uses this info to set the idle speed.

Idle should be around 750-800 when hot. Around 1000-1200 rpm engine is cold.