This issues started a month ago when driving to work one morning i pulled up to a stop light when the truck stalled out. Truck restarted with no issue pulled into that parking lot at work stalled out again. Took it to the dealership to have the issue checked out, couldn't find anything wrong. Then late last week after filling it up after driving all day got a no start. Truck would turn over but no fire. Truck was towed to dealership and they say it started up for them and couldn't find anything wrong. I picked the truck up and drove home and when put into park truck idled up to about 1300 rpm then came down to normal. Shut the truck off and restared truck fired fine and ran rough enough to make the truck shake for a couple seconds and clears up. repeated high idle and rough idle enough to take it back and it would not reproduce at dealership. Any advice? This is the 5.4 with about 32000 miles on it.

 

Might be the IAC.