i have a 96 grand 4.0 laradeo. i just bought it and was driving it home the other day and it just quit on me goin 45mph. i shifted into neutral and it started right back up while still moving. ran fine and went on home. the jeep starts and runs fine. the past few days i have been testing it by just starting it up and letting it run in the drive way. it will run fine for about 15-20 mins then quit. it will start right back up right away no problem and run fine then quit again 15-20 mins later. i replaced the ignition coil cause it had a crack in it and it still does it. anyone have any idea what this could be.?

 

Classic sign of the cam sensor going bad.

 

Also a classic sign of a intermittent connection at the PCM (common on 96-98 ZJ).
With the engine running give the connectors at the PCM a wiggle, if she stalls or stumbles you'll know you're on the right track.