Volvo D12 running rough when cold with white smoke

Common rail engine.... Different stuff. May be VNT, may be bad injector.

U need DDDL ore Mercedes Star Diagnose to find the problem.

Unit injectors and CRD are too different things

 

We tested the injectors they are ok. When I shift from 1 to 6th gear rpm go to 1900 but when I drive on interstate at 6th gear and up doesn't go more than 1500 rpms, black smoke and no power and acceleration

 

It's possible your VEB Volvo Engine Brake engage due of the VEB regulating valve malfunction and keep the exhaust valves partially open who generate a lot of white smoke due of compression (heat missing),i saw this problem sometimes in my area, it's worse when it's cold outside and also if the engine oil have a high milage.
Before go further i recommand you to change engine oil and filters because the Veb regulating valve is very sensitive . . .
Let me know !!
Ben

 

A egr can't be cleaned need to change it and it is very expensive. 100% you have a egr out needs changed I wouldn't take the truck to Volvo that will cost you a arm and a leg. Just saying find good local shop. If your In Indianapolis check out Indy Roadside Assistant 1-866-268-4355 good luck

 

So what was the problem and did you ever get it fixed???