That mystery has affected various models of cars, first thing i would check is coolant levels, i have come across water leaks that when hot go into a very very fine mist under pressure that find its way onto ignition leads and other crucial ignition parts, it may be as simple as that or an overheating ignition coil.
Auto-choke is stuck open
cold start switch on the side of or on top of the throttle body.
ECM
Most cars will idle high until the engine warms up. If your car continuosly runs high have the fuel system checked.
blown head gasket
this is caused from piston to cyl wall clearance when engine warms up the pistons exspand and the noise is less. DON'T WORRY ABOUT IT
I would check the transmission fluid level.
It COULD be a weak fuel pump. I have had a similar situation. In my case all I had to do was turn the ignition to RUN not start and let it sit until the pump stops humming. After the pump stops humming,then start the vehicle.
bypass the the line that runs into the radiator. witch is a trans oil warmer. reconnect both lines together
Yes. If the choke plate is sitting in there loose if can close by itself which would flood the engine. Also, without the choke you would have a very lean condition during cold start-up until the engine warms up.
It could, along with hundreds of other parts.
It's on the verge of vapor lock.