My 2007 was also affected the same way. Etennuly found that putting in the manual switch to the fan stopped the skip-spark type running. I did the same mod to mine, and finally put an end to all the endless "try this" scenarios. Believe me, I tried all the suggestions at the time. It was finally back to running great, right up until I found that I also had one of the 2007s with the bad cranks (43,000 miles - RIP).