not sure what could be going on here, but to start if you have a multimeter, check the resistance of the plug wires, and the resistance from one post to the other on the 3 coils and compare them (as in one coil at a time, both posts on that same coil). If you get wacky numbers between coils, and/or wires, you prob. need to start replacing parts. Prob. ought to change the wires out unless there a good brand, and new within the last half year or so just to rule that out.