One or more heater & AC (HVAC) air delivery and/or temperature mode door actuator may fail. This can result in incorrect air delivery or temperature. If this occurs, fault code(s) stored in the HVAC control module should be available to assist with diagnoses.Google+
Car Problem Reports
Chevrolet 2500 Pickup Heating and AC Temperature and Air Delivery Mode Door Actuators May Fail
Chevrolet 2500 Pickup Problem
Visitor, 1993 Chevrolet 2500 Pickup, 11,000 mi
When started on warm day its run a few miles and stumbles and stalls and when it cool out its hard starting and then stalls can't leave driveway.