I have a '91 Z-28 TPI that has died randomly on me now four times. Three times it has died while the car is idling and once while at driving about 55 mph. Twice it has died on long trips, over an hour, and twice on short trips, less than ten minutes. It always restarts given 10-20 minutes or so. Does anyone have any ideas? I have taken the car to a mechanic and he can't get it to act up on him. The service engine light comes on sometimes. It is giving me an EGR code but I have been told it shouldn't make the car shut off. I have been reading other threads and noticed similar posts referencing Opt-Spark. This may be a stupid question but could this be my problem and do '91 Camaros even use this system?

 

Your 305 doesn't have Opti-spark, it was first introduced on the LT-1 in 93'.