Heat gas or charcoal grill. Remove pork from marinade; discard marinade. Insert ovenproof meat thermometer into pork so tip is in thickest part. Place pork on grill over medium heat. Cover grill; cook, turning about every 5 minutes, until all sides are browned and thermometer reads 145°F (temperature will rise to 160°F after resting). Remove pork from grill; wrap tightly with foil. Let stand at least 20 minutes before slicing.