Ford Repair Questions? Ask a Mechanic for Answers ASAP
You can swap injector with another cylinder to see if problem moves if so replace, if not check wiring. If wiring is good replace the ficm.
To know for sure where the problem is swap the injector to see if problem moves. If not you will need to do a resistance test on wiring between injector and ficm to see if the wiring is the problem or the ficm is the problem.