I have a 2008 F150 FX4 Crewcab 5.4L FlexFuel 62,000 miles. Only mods are 33" Coopers and an Edge Evo. Over the last couple of months I have had an issue with what feels like a "surging" most easily noticed at highway speeds. The rpms and the speed don't change but you can feel it. I tried returning the Edge to the factory tune, didn't help. I have changed my fuel filter..seemed better at first but returned after a day or so. My thought is that it could be the fuel pump. I ran the tank really low several months ago and thought that I might have hurt the pump when I did. Now if I run the tank very low the fuel gauge doesn't recover right away after filling up. May not be related. Another idea is that it could be the transmission (I sure hope not).

The truck still has plenty of power and everything else seems to be fine. It isn't giving any codes. I have been reading through posts that seem to fit my issue but none exactly match up. So I decided to start my own thread.

I don't want to start throwing parts at the issue, nor do I want to take the truck to the dealership without having some kind of idea what is wrong.

Any ideas?

Thanks in advance.

 

Bump, anyone?