Timing adjustment 2001 Accent

[SidsDad]

Any suggestions on setting the timing belt, there is not a distributor. Had diagnostic done on car came back with the following codes:
P0300> Random/Multiple Cylinder misfire Detected
P0303> Cylinder 3 MIsfire Detected
P0302> Cylinder 2 Misfire Detected
P0301> Cylinder 1 Misfire Detected
The timing belt is set exactly as it should be. Is there something that I am missing in setting this a different way. I was told timing belt is off one tooth. Help Please!

[billyloon]

How many miles do you have on it? Have you ever replaced your spark plug wires?

[mazdatech]

thats where i would start too some ngk plugs and new wires.