Under acceleration I can feel a light shudder but when you get to cruising speeds around 50-60 mph it really starts to buck. I have no idea whats causing this and really need some help...

Truck is an 01 XLT with 4x4 and the 5.4. Any help would be great. Thanks

 

Did you happen to wash the motor out recently? If so, you might have water caught up between the spark plugs and the COP's. Happened to me a few weeks ago and sounds like the same problems I was having. Unplugged the COP's and used compressed air to blow dry the water. You can also use a clean rag and soak it up and let air dry. Hope this helps!

 

Either a bad cop or a spark plug...you can start the truck and let it idle and unplug each cop one at a time and find the dead one.You will hear/feel a change in the running as you unlpug the cop's that are good....if there is no change when you unplug one that is the dead coil.

 

Thanks ill check for moisture and and the cops.

 

westtn you nailed it. bad COPs on 1 and 3 thanks for all the help