Possible tranmission issue or dirty fuel system??
 

We have taken our 2005 Ford F-150 Crew Cab Lariat Edition (automatic) in to have the transmission and fuel system checked and they gave us the thumbs up for both.

We are not sure what is causing our issue, but here is the case. When our truck is in overdrive and you gradually step on the gas there is a hesitation. It feels as though the transmission is slipping. For example, if we are cruising on the highway and want to speed up by about ten miles an hour gradually it will create this issue. Once the vehicle is taken out of overdrive it appears to be fine. Every once in a while it will stop hesitating and feel as though the truck has a tremendous amount of power (feels like the gas pedal on a brand new truck). This truck has 68,000 miles on it currently. I am not sure what other information you might need, but please ask if there is any more that you would need. This is frustrating since the Ford dealer tells us there is nothing wrong. I have been driving trucks/cars for years, and this is not normal. Does anyone have any information or could you possibly shed some light on this. Any suggestions are appreciated. Thanks!

First thing I'd try is a basic tune-up (plugs and fuel filter). At the same time, I'd run some Sea Foam in the gas tank. This should eliminate the dirty fuel or missing spark that could be causing this.

ideas
 

Well, we took it in again and it threw a code for the coil. It had a bad coil so we are having it repaired and get it back today. Hopefully it will drive like a new truck again.