If I pin the pedal to the floor it will pull hard up to about 3200 rpms and then it hangs there and wont shift unless i let off the pedal a lil. whats up with this. I can def tell the loss of power is there.

I have the same problem mostly in 3rd gear. It will pull up to about 3K then just die like it has de-fueled for the shift that never happens. I let off a little and it will shift then pull as normal. I have a tuner but it is just a tow tune so not hundreds of extra HP.

when was the last time you changed fuel filter?

It has been about 6K miles since fuel filter change. The DIC still shows 60%.

I did some reading and seen that some people had similiar problems so I just went to change the fuel filter. Mine was indeed dirty. I'm going to go out and see if it helps some.

Check filter restriction:

http://www.kennedydiesel.com/images/Dmax-fuel-filter-rest1.gif

change your fuel filter. my truck was doing the same exact thing untill i changed my fuel filter. feels like a brand new truck

What's a good high flow fuel filter to use in these that will still do a good job filtering what brand have you guys been useing I have used wix and Delco whats your opinion?

There are no high flow filters get any major brand there mostly the same.

My truck isn't shifting at WOT but works fine in T/H. The filter didn't make a difference any ideas? I'm running a tow tune, transgo, and will change the stock filter tomorrow.

So what did you find fixed the problem? Was it the fuel filter?

My truck is doing the exact same thing right now. Drives and shifts normal until I pin it (engine and tranny are warm), then right when it tries to shift, it hangs and a ton of smoke billows out of the exhaust, and it will not shift until I let off the throttle a little.

Same thing happens to me.Hope someone chimes in with what the f@&# is going on.

Here is another one I can check off as it is happening to me lol! I just changed the fuel filter a week earlier before anyone askes. I have tried changing my shift points and it doesn't seem to change the problem 3/4 throttle and it shifts great etc...???

yep, fuel filter did the trick!

X2
I bad tank of fuel can use up a filter. Those running tunes you could be draining the rail of fuel too.