In a bowl, combine the first five ingredients. Pour 1/2 cup marinade into a large resealable plastic bag; add pork. Seal bag and turn to coat; refrigerate for 8 hours. Cover and refrigerate remaining marinade for basting.
Drain and discard marinade. Using long-handled tongs, moisten a paper towel with cooking oil and lightly coat the grill rack. Grill pork, uncovered, over medium heat for 15 minutes on each side or until a thermometer reads 160°, basting frequently with reserved marinade.