Ok, so I am curious as to what causes a carburated engine to idle differently when it is cold OUTSIDE, and Idle completely different when it is warm OUTSIDE. My truck idles perfect when its like 58 degrees or colder outside, as soon as the temp outside gets above like 58 it idles really low and sorta rough. It does this regardless of the engine temp, only as a result of the outside air temp. What would cause this?

** I have a aftermarket air cleaner installed. its just a chrome circular one, which means the air cleaner no longer has the tube from the heat shield on the exhaust manifol putting hot air into the air cleaner assemby.**