drove the car all day, then on the way back home its missfiring like mad. i pulled over and let it idle, when you pull 1 &2 leads out its still idling, when you pull out either leads 3 or 4 it dies. all of them are still sparking, and I've swapped 3&4 plugs with 1&2 but its still doing it. its down on 2 cylinders ( 2 closest to cam belt) and im unsure as to what it could be. im waiting for my mate to txt me so i can try his dizzy cap. any ideas??