My car was running fine except it had to turn over

Possible burnt rotor, take off the distributor cap and remove the rotor. Flip it over and look for a black dot ,this is where the spark is going into the ground instead of out the spark plug wires.Rotor looks good?Check for spark,pull of a spark plug wire and insert a screwdriver in the end of the wire. Holding it only by the handle, hold the screwdriver a half inch away from the engine and have someone turn the motor over.(Don't touch anything metal or you'll find out what 30,000 volts feels like!)You should see a bright blue spark the full distance between the driver and the engine.If the spark is yellow or will barely jump the gap replace the coil.It's back firing so you have fuel,lastly and definitely the worst case scenario,you've lost the timing chain-belt.Good luck!