i have a 93 chevy dually 6.5 diesel with the banks power kit. When you are driving the truck it will shift first gear but then when it trys to go into second if falls on its face but it will only happen when the trucks cold or going up a hill. i just put a brand new injection pump on the truck. i am running out of ideas and money please help mee   Thanks  

lift pump maybe?? is it blowing smoke??  

it will blow black smoke but when this is happening its white which would tell me its sucking air?  

lift pump

http://www.dieselpowermag.com/tech/general/0801dp_1995_chevy_k2500/index.html

here is there website
http://www.heathdiesel.com/

also just to be sure ask around here
http://www.competitiondiesel.com/
and here
http://www.thedieselgarage.com/

Hope this helps