I had the tensinor go out on my 98 s70 just as i was starting it not sure if it did any valve damage yet. When i took the cover off the belt had road out on the cam pullies and eat the time marks off the cover. I had found out that the settings should be at 11 and 1 . when i set it by guessing it turn free but when i tried to start it turned like it had no compesion. If it is off by a one of the teeth would that keep it from not starting

 

If the timing jumped when you went to start it most likely you have bent valves.