My 1972 T, which never really accelerated too smoothly, is really getting bad: it's started lurching and kind of bucking when any pressure is put on the accelerator at all. It idles ok, and if you really, really ease it up it's a little smoother, but it's almost undriveable the way it is behaving. Anybody know what may be going on? I have mechanical fuel injection and I'm thinking an injector may be stuck? I'd appreciate any suggestions.