Pontiac Repair: 97 Grand Prix timing, crank pulley, crank shaft

Question
My Grand Prix quit on the way home the other day. Since then there is a tapping on the front of the motor, bad fuel mileage, and hesitation while going down the road. The drive belt split 2 ribs off(didn't break) and the part that split off wrapped around the crank pulley. Is it possible that caused a jump in time or could the crank position sensor just be off a little and the tapping is one of the cylinders not firing at the right time?
Thank you for your time.

Answer
Hi Kenneth:

My guess is that the frayed belt damanged either the crank sensor of the back of the balancer. on the back of the crank shaft halancer is 2 metal rings with notches in them. Those notches are for the crank sensor to detect the engine is running at at what speed. if the belt got stuck in ther and bent those rings a bit the noise you heard was the rings slowly grinding away at the sensor. So my guess is you'll need both parts. But without seeing it's hard to say for sure but I have seen this happen before! good luck :}