The coils will have to be replaced. The way that these coils fail make it difficult or impossible to test for unless you have an oscilloscope and know how to use it.
Please note that Ford will replace the coils and the valve cover gaskets at no cost to you if you have less than 100K miles. See the letter below. You may need to take a copy of it with you to the dealer.
http://www.allstatetrucks.com/Recall...20bulletin.pdf