2 pork tenderloins (1 pound each), cut into 3/4-inch slices
In a small bowl, whisk brown sugar, salad dressing, pineapple juice and soy sauce until blended. Pour 1/2 cup marinade into a large resealable plastic bag. Add pork; seal bag and turn to coat. Refrigerate overnight. Cover and refrigerate remaining marinade.
Drain pork, discarding marinade in bag. Moisten a paper towel with cooking oil; using long-handled tongs, rub on grill rack to coat lightly.
Grill pork, covered, over medium heat or broil 4 in. from heat 5-7 minutes on each side or until a thermometer reads 145°, basting occasionally with reserved marinade. Let stand 5 minutes before serving.