coil

I worked for a company that built OEM coils for 8 years. I was in every phase of the creation of an ignition coil. I have fired coils in tests that would mimic you driving at top speed, while sitting in a thermal shock chamber bouncing in temps from -20F to 250F for over a week. I have never seen a coil fail. Failures only come back to us and were related to manufacturing defects. Defects usually are from contamination, poor solder connections, or wiring that has a cut in the coating (pinholes) and over time will eventually short. We are talking like 5 a year here at the most. 750,000 coils a year. The only thing I can tell you is that if your going through 9 coils, you may want to check your ignition module. A coil fires from a square-wave signal and that signals varies in frequency depending on your RPM. Your module sounds like either it has lost the ability to control the voltage and or frequency. Regardless, most of your ignition problems seem to come in this order. #1 Worn Plugs, #2 Rotor and Cap wear #3 Plug Wires (usually burned on headers) #4 Ignition Module #5 Ignition Coil