Why does a 1993 Ford F150 4x4 pickup stall out after it heats up?

It sounds as if you have a bad ignition control module. It would be located on the distributor. On some of these vehicles, the module was moved over on to the side of the left fender. Ford had a lawsuit against them for these modules, but the time to submit claims against them has expired. It is also referred to as the thick film ignition (TFI)module.