Could be the coil pack. But it could be an internal problem with the cylinder too, like worn valves causing low compression. I would get a spark tested and see if that cylinder is losing spark. If it is, then it could be the coil pack. If not then I would check the compression to make sure the engine is not worn internally.
Another thing it could be is the injector. You might try swapping to see if they problem follows the injector.
Thursday, May 3rd, 2012 AT 9:29 PM