Hinge failure on XJ's, especially 2-doors, is pretty common. If the hinge is tearing away where it is welded to the unibody, it can be rewelded, but to do it right requires that the door and fender come off. When the door gets far enough out of alignment, it will catch on the edge of the fender. Sometimes you can adjust the door on the hinge, or just bang it back toward the body, but it's likely that the only real fix will be to repair the weld. If the door check is broken, you can replace that, and it will help keep the door from opening out too far and denting things. The check mechanism is not strong enough for the weight of the 2-door if it is flung open, and will often even bend out the frame of the door where it is mounted. When this happens, the hinges reach their built-in limit stops, and flex out from the body, eventually fatiguing the welds.