Need help with Mack e7 dying

Have a new to me 94 mack with e7. Drove it home 2.5 hours the other day with no issues. Now when I start it, it will run right at 30 seconds and die. Then you can start it right back up and same deal. It runs fine when it is running. A lot of people have recommended coolant sensor reading low, but it appears to me it’s been unplugged since I bought it as plug in radiator is dirty. No sensor on overflow tank. There’s a couple sensors on wires under hood that have jumper wires plugged into them so guessing one of those is for coolant. What else should I check? Oil pressure is also reading fine