tps adjustments

[my0460]

Does anyone know if you can adjust the tps on an 04?

It seems like i have to push the pedle a 1/2" before the truck responds.
I can move the pedle from the rest down a 1/2" slowly and it will do notting, till 1/2" . I can push it 1/4" and it will do nothing,let off nothing. back on nothing till 1/2".

This is my first diesel. so i'm learning alot of new thangs.
thanks