I am an oldtimer looking for help. We are trying to fix my Son's girlfriend car, A 1996 Mazda 626 V6.

The belt drive for the alternator came off the crankshaft pulley so the alternator stopped working but the engine ran fine. We replaced the pulley with a new one but now the engine won't start and it sounds like it is out of timing. I noticed a sensor next to the pulley but don't know what to try next. Anyone know what the magic answer is?