all of the diesels i have had, 1st gen, 2nd gen, and now 3rd gen have bad power consitancies, one day they run like a bat outta hell and the next they feel kinda sluggish, every cummins i have driven has been this way, why? Is there any driving techniques that i can do or any fuel additives that i can use that will really help, I change my fuel filter and clean my air filter every oil change (4500 miles) and run power service diesel clean additive almost every tank, thanks for your input

 

Also how can you lock your torque converter at lower speeds around 45mph or so, can you?

 

The speed thing is all you........ Happens to me also. Install a TC lockup switch to lock the converter manually.

 

how easy is that switch install

 

Use the search function and do a search for TC lockup switch.