Riddle me this!

[emerritt82]

i have a 1997 psd 140k miles, i have a strage problem! if the truck sits for more than a day or so the first time i start it it runs awesome perfect power, shifts good, ect. until the first time i shut it off and start it again. then it hesitates on takeoffs and doesnt have as much power overall. it is fine at higher rpms but seems to struggle getting there. i have replaced...
*pcm
*ipr
*ipc
*oil pressure sensor
*oil temp sensor
*fuel pump
*rebuilt trans
*cam sensor
*fuel filter

i just dont get what could change after i shut it off and start it again. it is like clockwork though! any help would be very helpful thank you!