Add pork to gallon-size zip-top bag; add Mojo Piña and seal bag. Massage to coat pork in marinade; transfer to refrigerator. Marinate at least 4 hours, or until ready to cook; discard marinade.
Heat grill to medium-high heat. Add pork chops to hot, greased grill grates. Cook, flipping once, until well-charred and cooked through (internal temperature of about 140°F), 13-15 minutes. Brush onions and pineapples with oil. Grill, flipping once, until well charred, and onions soften, about 15 minutes for onions and 3 minutes for pineapple.
Transfer pork to platter; top with onions and pineapple; serve.