Cook on outside grill for 30-35 minutes, turning every 5 minutes. Remove and let rest for 10-15 minutes before slicing.
VARIATION: To bake without pre-marinating, use a larger 3-4 pound tenderloin and place in a baking dish lined with 2-3 layers of foil. Place meat in pan, salt and pepper and pour bottle of teriyaki sauce over along with Worcestershire sauce. Pack brown sugar on top and seal foil, closing tightly. Bake at 300° for 3-3 1/2 hours. Open once after 2 hours while cooking and turn over. Close foil and complete cooking. Tenderloin will fall apart with fork.