Strange thing!! I was reading the posts and i came across the info of the coils that fire each cylinder. left= #1 and #4, right= #2 and #3. I'sure I've been running mine with left= #1 and #3, right= #2 and #4 for about a year. As it started running on 2 cylinders recently, I decided to swap them and although it took ages initialy to start, now it runs again in all 4 cylinders. very strange!