Doesn't the TFI tell the coil when to fire? Swap the TFI. Most likely gonna screw up your timing a bit but just unclip connection and remove the two screws and it should slide down. If it isn't the problem you have a spare just in case and it is a good thing to have IMHO. When reinstalling make sure to put some paste that it comes with on the back of the module and slide it back up in place and replace the screws. The only difficult part of swapping it out is that it is located in a PITA location.