I have a 2003 6.0 F-350. The engine has roughly 120,000 miles on it. Of course with that many miles on the factory components which have 196,000 on them, it's going to have some issues. The HPOP, IPR and ICP was all replaced around 20,000 miles ago. Given that those are good parts, I don't believe they are my issue.
The truck starts fine in the morning when the engine is cold, but when warm is walks up to idle. After walking up to idle for the past few weeks, the truck would stumble, catch itself and rev back up, all fluctuating from 590-760 RPM. It would do this until I started driving it. Later on that same day, the truck started sputtering, missing, bucking, and I noticed a bog-down-type lack of power. The idle was very shaky, and the throttle was haywire. The slightest touch of the pedal would have that thing from idle to about 1100, and if held there, it would eventually drop down, while my foot is in the same position. While at idle, if slowly letting off of the brake, the truck would "shiver" and inch forward, not the normal smooth-moving it normally would. There is also a lack of power and a major increase in turbo lag along with this. This problem used to be intermittent, but now is getting more frequent. I run 5w-40 T6 up here in IL. I run Diesel Kleen in every tank, and the fuel filters were just changed. Oil only has 1100 miles on it. Ficm while truck is running good is at 48-47.5 volts from idle to WOT. IPR and ICP pressures are in the clear (don't remember exact numbers). Keep in mind that the truck was running good when I got these numbers (of course it doesn't act up with the scanner on it). However, at idle the batterys were getting 13.4V and 13.9V. The FICM input voltage was 13.1 I believe, which seems pretty low. Sorry for the long post, this thing is just driving me crazy.
Thanks in advance!