My grandmother has a '92 Sable and it has an intermittent dying issue. It cuts out abruptly (whether parked or driving, at any speed), but it only happens a couple of times a month. When it dies, it will turn over fine but won't restart right away. It has to sit for a while (10-30 minutes), and then it restarts fine. She's taken it to a shop but they couldn't figure it out. I'm going out soon to take a look but I need somewhere to start, I'm not familiar with American cars. It sounds like an electrical issue, hopefully it's something I can fix.

TIA,
Brian

check your fuel pump relay. The reason why it dies because the oil pump relay is also a back up for your fuel pump relay. American cars have this. When your engine heats up and your oil heats up the oil pump relay causes to de-energized to cool off. And then the car start again when the car has cooled down. So check your relay.