I have a 2005 F250 6.0L with and Idle problem. Over the last month, when the engine is started, it will idle at "half" speed (approx 300 RPM). The accelator peddle has no effect. I can push the peddle to the floor and nothing happens. It will idle at this "half" speed for 1 to 2 min, and then idle up to normal and runs fine. A few times it took several times to get it to stay running at "half" speed, then wait the 1 to 2 min until it would return to noraml. I replaced both fuel filters. Problem still present. I finally took it to the shop and they said the crank sensor was bad. The sensor was replaced, and 2 days later same problem. Took it back to the shop, and again the crack sensor was bad. Replaced it, and again same problem. No other codes showed up. One other sympton I have noticed is a hesitation when accelerating from a stop. Not sure if this is a sympton or I am just sensitive to the problem. Anyone have any thoughts as to the problem?

 

Moved to the 6.0L Powerstroke Diesel forum.

 

I would check your FICM voltage, battery voltage first (cheap and easiest)

Then I would look into a failed injector/injectors...