Trim fat from pork. Place tenderloins in a large heavy-duty, zip-top plastic bag. Combine soy sauce and next 7 ingredients in a small bowl; stir well with a whisk. Pour soy sauce mixture over tenderloins. Seal bag, and marinate in refrigerator 8 hours, turning occasionally.
Remove tenderloins from bag, reserving marinade. Place marinade in a saucepan; bring to a boil. Remove from heat. Coat grill rack with cooking spray; place on grill over medium-hot coals (350° to 400°). Place tenderloins on rack; grill, covered, 7 minutes. Turn pork, and baste with reserved marinade. Grill, covered, 7 additional minutes or until a meat thermometer inserted into thickest part of tenderloin registers 160°.