Misfire on cylinders 7 and 8 with cylinder 8 having a larger percentage of misfires. In determining cause I moved the coils to different cylinders; coil from 7 went to 5 and coil from 8 went to 4. New misfire data showed cylinders 3 and 4 misfire. Conclusion: Coil from #7 was good and from #8 was defective. Replaced #8 coil and cured problem. I cannot begin to explain why #8 coil caused #7 to misfire nor can I explain why moving it to #4 caused #3 to also misfire. I just know it did so if you run into something like this my experience may save you a lot of time.

Tim Kuehl
Owner/Technician
Old Geezer's Garage
Montgomery, Texas, USA