I have had my 6.5 for prolly 3 years now and have had to do very little to it but just within the last 3 months my injector pump was going bad. No biggie, i replaced it and the problem was solved, but now it is wanting to do the same thing. It doesnt like to start when the motor is hot( about 200 deg.) and it is doing something really funny that has never happend before, it will start fine but it has no power. Its to the point to where i can barley take off in first gear, even at that i have to ride the clutch but its only when it is cold. When it warms up it is fine on take off. The other problem is just normal driving it has hardly any power, it only puts out 6 lbs. of boost, and i know the turbo is fine because it will surge and go up to about 12 where it was before all this started happening. When it surges it is usually under heavy acceleration going up hill, i put my foot down harder on the gas and it will build up then die off really quick. Do you know what my problem could be?

check your fuel pressure while driving sounds like a weak or inoperative lift pump

check your fuel pressure while driving sounds like a weak or inoperative lift pump
X2....also check out you fuel filter, turbo(look for shaft play, broken/chipped blades).

If yours has a vacumn pump which controls turbo waste gate you might check for vacumn, leaks in lines ect. add some info on your truck to your sig. it will help narrow down the problem

I have replaced the inline fuel pump and the fuel filter, still having the same problems. Would it be possible that the injector pump went bad again?

Did you bleed the air from the filter?

did you verify the lift pump is working might be a bad opsu

Yes i bleed the air from the filter and made sure the pump was working, I even made sure all the lines were tight on the pump and cracked the lines on the injectors. I cant help but think that the pump went bad again, it is either the injector pump or the injectors i have replaced all the fuel lines and everything before the fuel filter housing. This is the old style manual pump

I cracked the lines on the injectors to make sure no air was comin out there.

do the head test to check head gaskets.
w/ engine cold remove T-stat upper housing and T-stat. next, remove serp belt. start up to operating temp, use a hand held thermo placed inside coolant at the T-stat housing. run to operating temp and check for air bubbles in the housing while it is running. if you see any bubbles in the left/right bank, or both, you have either bad heads or gaskets. make sure to use the thermo, don't want it to overheat.