Cm870 low boost high egt

[Oilysnowman]

Hi, I’m hoping someone might be able to help me with a problem I’ve got on my cm870.
It’s got RR programming
New turbo
New head
New cams and rockers
New fuel actuators
New turbo control module
Injectors test good
Recent overhead done
Passes all Insite tests

But here’s the problem, when it’s warmer then 0 Celsius, it works really well, colder then that, it works terrible. Low boost on pulling and engine brake (30-32 pulling 20 on engine brake).
When it’s cold out, I can block the radiators with cardboard, and it works very well empty, but loaded I have to let the coolant rad get some air, and by the time it has enough to sufficiently cool, the low boost problem is back. Egt run at 900-1000 when it does this, and it also has steady black smoke.

On Insite it shows EGR temp is a fixed100f
Ambient air temp is a fixed 72f
Turbocharger inlet air temp is a fixed 118f

All my other sensors seem to show correct readings, I’ve done the cold engine sensor compare multiple times, and they match.
Checked fuel pressure with a manual gauge and it showed 275 psi, Insite showed 255.

I’m sure I’m forgetting some info, but that seems to be the long and short of it. CN anyone help me with this? Thanks!