Ahhh, good ol Motorcraft plug wires, been through three sets in two years now. Real easy way to tell, go to a dark parking lot or something at night........have your engine running and raise the hood. Throttle the car and watch the wires, if you see the wires lighting up.....then replace them. Semms to cure mine every time.......problem seems to have started after I installed NGK plugs......went back to autolites and havent had problems since.
