Trouble with McCormick CT28H 4wd w/loader

Bought this tractor from a dealer with 18 hours on it. It had been sitting on another dealers lot that went out of businesss for some time. Shortly after getting it, the thing quit running and wouldn't turn over. They came and picked it up. Returned it a few days later after installing a new starter wiring harness and it started right up.

However, now it has stalled out 4 times in two days. Just stops running. I can hear the glow plug making its noises when the engine shuts off, key is ofcourse still turned to on position when it quits. It starts back up each time. Happened the first time right after seeding, twice during seeding (PTO engaged), and once within a few minutes of starting before ever getting out to the pasture. Happened in middle gear and at different throttle speeds. Going to let them know this new problem on Monday. Sure hope I didn't buy a Lemon! Any thoughts on what the cause might be?

Thanks! Rob

If there was an electrical problem before, I may lean in that direction, but without actually replicating the problem and testing some stuff when it happens.....that's a tough one to call. Good luck!