Re: Miss fire
Ignition timing is controlled by the PCM, using several sensors for input. Like rpm, MAP, TPS, coolant temp and vehicle speed. If there is a real misfire, it should set a code P030X, where the X is the cylinder number, or P0300 for multiple cylinder misfire).
But how are the basics: are the plugs clean and not worn, is the air filter clean?
A dirty fuel injector will disturb the spray pattern and can affect the burn pattern in the cylinder, giving less power then it should. You could try some injector cleaner in the fuel.