What's happening is that the sugar in the marinade is scorching from the heat; it's pretty common. What I think you want is caramelization, where the sugar turns to a syrupy substance.

I would suggest that if you're going to use the marinade, that you grill your chops. OR steam the chops (cook over a medium-low heat with a lid on the pan and about 3 TBS of water added, and brown them during the last 5 minutes or so. Or you could cook your chops as you normally would, using the marinade as a brush-on rather than something that is on the meat the whole time.