1997 Chevy Blazer stalls while driving sometimes

This car inadvertantly just stalls out when driving or coming to a stop. There is a delay in the gauges when starting and the other day the key stuck in the ignition. My husband took the gizmo off under the steering column and the housing and a release pin were too hot to touch. It has a new fuel filter, fuel pump and the throttle body cleaned. Computer diagnostic has been run 4 times with no problem showing up.