1989 Buick Century Car sputters to stop then won't start ba

Electrical problem
1989 Buick Century 6 cyl Two Wheel Drive Automatic

I deliver mail. Halfway through my route the car will start acting like it will stall and eventually it does. Then it will not start back up until it cools off, (usually in about an hour). When the key is turned over it makes NO NOISE, just dashboard lights and radio will come on. It does not overheat. It also seems to use more gas than usual when this happens. I've had 2 coils replaced. A new fan, & new battery. No corrosion on battery or connections, cables are ok. Can you help me. Thanks Sharon