Car starts then stalls???? Possible Thermac system issue? The **VERY UNIQUE** 1984 Corvette relies on HEAT off the manifold to run/idle properly during warm up. Per the FSM, this is the first place to start looking for problems. The Damper Doors not working properly…cause a lot of problems. The thermostatic air breather assembly works off heat from manifold from cold start-up. My driver side (snorkel) plastic inlet elbow cracked off…brittle. All needs to work together, heat sensor and damper door diaphragm motor. Lot of times people want to look at something very serious as the problem….not always the case.