1996 Ford Contour The car ignition cranks but engine won't

I recently started driving this car. We found a problem with the air intake sensor that was causing it to jerk when driving and not get up to speed. We unplugged the sensor and it was working much better. We also think the timing belt might be a little bit looser than it should normally be. I was driving it to a park and before pulling in the car shut off all the lights turned on and the steering wheel didn't lock but it got real tight. I tried to start the car again but all it would do when I tried to start it is the ignition would just crank and the engine wouldn't start. We couldn't hear the fuel pump starting when you just turn the ignition before starting it. We found a switch where you could turn it on or off and switched it and we could hear it again. It still was doing the same problem. We replaced the fuel filter thinking maybe the car wasn't pumping gas into the engine but that wasn't the problem either. I don't know if there is something wrong with the engine,starter, or maybe electrical. Any help would be appreciated.