Unusual idle at start up

Alright... I'm hoping this will be simple...
I have a 96 SE with the 4 cyl engine
when I start the car after it's been sitting for a while, whether its hot or cold outside, it needs at least a few minutes to warm up... After being started for about 30 seconds.. the idle begins to fluxuate for another 30-45 seconds... the idle is at 1500rpm until it warms up, then goes down to 800rpm.

Any thoughts?

Idle air Control and the throttle body may need a cleaning.

Also clean the mass airflow sensor. When it gets dirty it will cause fluctuation in the idle as well.