Warm engine miss/ running rich

I have a '93 ford F150 supercab, 302, automatic, 4x4.

Here is the problem:

After the engine reaches operating temperature and I proceed to drive it around for 10-15 min longer. It starts to miss at low RPMs and seems to be running a little rich overall. When its cold it runs fine.... no problems.

I have already replaced the coolant temperature sensor, aircharge temperature sensor, fuel filter and ignition module. I have spark on all cylinders. And fuel pressure is normal.

I am right now in the process of running a couple of tanks of gas with fuel injection cleaner through to make sure there is no debris in the injectors.

Any ideas as to what else this might be??? Let me know if you need anymore information on the problem.

Just went threw this with my 01, i had moisture in a spark plug boot. I actually took each plug out cleaned it put dioelectric grease on each one replaced it perfect now. Like yours mine was fine at startup within a couple minutes it was there...DAVE

Thanks Dave... I will try it and get back to you.... Calvin

I bought new plug wires and tested it out.... took it for a 40 mile drive.... seems to have helped.... I will update if there is any change. Thanks again