Combine first 10 ingredients in a shallow dish or large zip-top plastic freezer bag. Cut pork diagonally into 1-inch-thick slices, and add to tequila mixture. Cover or seal, and chill 1 hour, turning occasionally.
Remove pork from marinade, discarding marinade.
Grill, covered with grill lid, over high heat (400° to 500°) 3 to 4 minutes on each side or until done.