I have a 87 Z24 Cav. When i start the car it runs for about 60 seconds then cuts off. I can restart the car after it dies and it will do the same thing. Any ideas? 2 door convertible, EFI. Have replaced the coil packs fuel pump and computer.

 

Sounds like the fuel pump is doing its initial run when you turn the key on but not running when the motor starts. You need a diagnostic chart to see where it feeds from. I am away from my books so cant help on that. Some feed thru the oil press switch so if the oil press drops it kills the pump. Some have a collision switch that shuts the pummp off in case of a crash. Hope this gives you some ideas.