If you are turning the engine over, have spark, and it does not start you must not have fuel. Make sure the fuel pump is running and you have fuel pressure. Unless something big has happened it should start and run. check timing. Pull the #1 plug rotate engine until timing mark lines up on crank, piston should be very close to TDC, if it is not maybe you have a broke timing chain. Very unlikely, but still posible. If you have air, fuel, and spark, and turn the crank it will run.