my ignition key problem
 

My ignition is stuck in one position I can remove my key. But I can't start my jeep it won't turn far enough forward. It stops at the on position I have to jump the starter with a screw driver and force the key backwards to turn it off. I tore the top steering column apart and changed the switch and it still does it . I don't see anything else bad. I just haven't checked the bottom of the rod by the steering column. I need help any one got any ideas or had this problem.