2007 5.4 - Starts right up, BUT(!)

[Steve Hartman]

My Exy w/201,000 on it starts up just fine after sitting overnight.. About 15 seconds in it runs rough for another 15 seconds, then runs fine again. Very annoying. Any Clues?
TIA, from a very ol'man!

 

[Trainmaster]

Fuel delivery problem of some sort? Put a pressure gauge on the fuel rail and watch it.

 

[Gary Waugh]

Change the inline fuel filter, it’s probably blocked..