I had an msd ignition on my car for around 5 months and then i decided to turbo the car. Running a msd ignition with boost ruins the distributer which i didn't know. I tried swapping wires, unhooking the msd components and swapping back to the stock ignition coil. Every time i hit v-tec it broke up real bad, missfired in three cylinders. I bought a new distributer hoping that would be it and it was. If any one has a similair problem, i recomend doing this and swapping plugs. The carbon from running rich doesnt help either

 

If you're boosted, you should already know to check your plugs regularly. Get a good tune and your problem should be a rarity.