I have had several early 90's Luminas (GM W body vehicles) with the same symtom in my shop. When the vehicle stalls how long does it take to happen, from the time he starts the engine to the time it stalls? Is the engine completely warmed up to operating temp?
The usual culprit is the ignition module. What happens is the circuit board in the module gets a hair line crack over time. As the engine warms up the circuit board warms up, it expands the crack, causes a short, and shuts down the engine. After the engine (and module) cools, which takes about a half hour, the engine starts right up without a problem. Since the onboard computer is OBD1, it does not store codes and therefore there is no evidence of what caused the fault.
I, of course, can not say for sure that this is your vehicles problem. This is just an idea, a problem that I have encountered many times on the same model of vehicle. Hope this helps you, let me know.
Thank you,
Dan
Friday, February 12th, 2010 AT 4:04 PM