I have a start issue with my 1994 YJ 2.5 I just bought it last week and it runs great but after the engine reaches operating temp it will not restart after shutting it off. After 15-20 minutes it will fire right up and runs fine. Also the service engine light comes on after 20-30 miles but goes out when I restart the engine after the cooling down period as I would call it. What’s wrong with it? Need some help!