Trouble with 1980 Olds Cutlass Supreme



I have replaced my battery twice. When I start the engine sometimes it sounds funny and the rpms fluctuate. It takes longer than usual to warm the car up. Also, sometimes it has died on me while driving and the check engine, low coolant, service lights come on. After a few minutes I am able to restart the car. Does anyone have any suggestions? I would greatly appreciate any advice. Thank you!