DougDiesel

I have a 2007 F12X with 107 hrs on it. The problem I am having is when I go wide open throttle sometimes it runs the way it should and other times it does not. Sometimes it will run 6000 rpms then if I slow down and hit the throttle again it will only go to 5000 rpms. It still runs smooth but it doesn't have all of its power. I have checked the waste gate and it is moving freely and the actuator is working right with air pressure. I have replaced the turbo control sensor put in new plugs and changed the oil all of which looked fine. It seems like a fuel problem but I don't know what to change if it is a fuel problem. I tried to look at the gas sock in the fuel tank but there isn't enough room to get the fuel pump out of the tank. any suggestions would really be appreciated.