Heat grill or smoker to 250 degrees. Cut pork loin into 2-inch cubes. Season pork loin, sweet onion, red bell pepper and pineapple chunks with rub.
Thread pork loin, onion, pepper and pineapple on skewer; repeat until length of skewer is almost full. Repeat with additional skewers.
Put assembled kebabs in large resealable bag and add teriyaki marinade. Carefully remove air from marinade bag and refrigerate 20 minutes.
Remove kebabs from marinade bag and place on grill over indirect heat; cook 12-14 minutes, remove and set aside.
Increase grill temperature to 400 degrees. Sear kebabs at high heat, until caramelized. Using meat thermometer, check pork loin cubes for doneness; remove from heat once pork reaches internal temperature of 145 degrees.