Place pork tenderloin in large crockpot
Combine pineapple juice from can, soy sauce, preserves, garlic powder and pepper in a mixing bowl and mix thoroughly. Pour over the pork tenderloin and add all but ¾ cup pineapple chunks.
Set crockpot on low and let cook for 6-7 hours. Pork must reach an internal temp of 150ºF, but for this recipe, I like to let go well past for tenderness.
During the last 30 minutes, shred pork and let cook in juices the remaining time.
Heat corn tortillas prior to serving.
Add shredded pork to tortillas then spoon pineapple BBQ sauce over the pork.
Add desired amount of Pineapple BBQ Sauce
Combine all ingredients in a blender or food processor and puree until smooth.
Pour into a small saucepan and simmer over medium heat until sauce thickens.