Same thing happened to me. It took me a while to figure out it was the ignition module. A good thing to do when you get a new 5.0 is to get a new module, coil, and pickup coil. This should solve your problem. However, MAKE SURE YOU GET THE PARTS FROM A FORD DEALERSHIP! An aftermarket ignition module will start giving you the same problems again. I bought one from autozone and it started acting up a few months later. Now i got all new parts from ford, and it runs like a dream. Hope this helps.
