Cummins struggle and pulling hard at takeoff

Hi. I have a 2007 volvo 780 with cummins 500 isx and 13 speed transmission. With the engine cold the truck struggles for about 20 minutes, i mean the turbo pressure is up to 30-35 psi and the truck is pulling like its going uphill. This happens with an empty trailer. Whith the engine warmed up if i restart , it does it again but only for a couple minutes. Than oll of a sudden in about 2 seconds the turbo pressure drops to about 5-10 psi and the engine Becomes quite and smooth until i turn it off and restart it again. Any ideas would be greatly appreciated. Thanks

 

Thanks for the quick respons. There are no codes at all.

 

That is the thing. I never rev it up to 2000. Let's say im driving down the road with an empty trailer with the cruise control set to 65, the rpm is around 1300, turbo boost is a little over 30 psi, fuel consumption is like doubled and the engine sounds like its pulling hard than after about 20 minutes the engine noise goes away , the turbo pressure dropes to like 5 psi , the fuel consumption drops to normal and the engine feels to pull strong. That whole change happens in about 2-3 seconds. Than everything is fine until i turn off the Engine and i restart it again. I ts been doing this for about a half a year. I get the fuel filters changed at every pm service. Thanks for the quick respons.

 

It only has egr but even that has been deleted.