In a mixing bowl, combine pineapple juice, achiote paste, white vinegar, minced garlic, onion powder, ground cumin, chili powder, black pepper, and salt. Mix until smooth. Slice the pork shoulder into thin strips and coat thoroughly with the marinade. Cover and refrigerate for at least 1 hour, preferably overnight.

Preheat your grill or skillet over medium-high heat. If using wooden skewers, soak them in water for about 30 minutes.

Thread the marinated pork onto skewers or place it directly onto the grill. Cook for about 5-7 minutes per side, turning occasionally until charred and reaches an internal temperature of 145°F.

Once cooked, remove pork from grill and let it rest for about 5 minutes. Chop the pork into bite-sized pieces.

While the pork rests, heat a skillet over medium heat. Warm the corn tortillas for about 30 seconds on each side until soft.

Assemble the tacos by taking a warm tortilla and filling it with a generous portion of chopped pork. Top with diced pineapple, chopped onion, and fresh cilantro. Serve with lime wedges.