Hi Guy`s , My Boss has a 2001 F250 4X4 Pickup 5.4 Liter , He say`s it run`s like it`s on 6 cyc. some of the time , First thing I had him do was change the Fuel filter , No good , next thing was a tune up , To my surprise No wires no cap no coil , He had someone check those caps on top of the engine that connect to the spark plugs , OK , I am at a lose , Alittle help PLEASE .PS only 80.k on the truck if that makes a difference .