I have a 2012 6.7 with a smarty Jr on the 40hp tune, 5" turbo back, sinister egr delete kit, and air raid intake.. for some reason if I give it half throttle it seems to work fine.. but at full throttle it acts like its defueling. Happens at about 2500 rpm.. any suggestions on what this may be?

 

whens the last time you changed fuel filter?

 

It only has 10000 miles on the truck and about 5000 on the fuel filter but honestly I didn't even think of the fuel filter being clogged up.

 

I would say its your traction control, mine does that also there should be a button beside yer tow/haul button. Its kills the power cuz it starts spinning. Might not be whats wrong with yers but thats what mine does till i turn that off. Hope this helps ya

 

With traction control on.. does your truck do it at 70mph and higher?? Because that's when i notice it the most.. when passing someone at a higher speed.

 

No as long as im not spinning its fine! Must be something else. Does the smarty junior have any setting on the programming to make it defuel? Like to much boost or egt or something like that? I have never had a junior.

 

If you have a mm you can look at fuel rail pressure, make sure your not running out of fuel or loseing fuel pressure. I've seen also one bad tank of fuel ruin a fuel filter.

 

possibly you need the fuel rail shim kit or plug?

 

Any luck figuring out what the problem is? I seem to be having the same issue under hard acceleration. MADS says it is a software issue and we will have to wait for an update but I find it hard to believe that every 2012 with a JR is having this problem.