VW t5 2,5TDI AXD lint - The engine lugs when adding gas in the whole range.

Hello. I am "New" in the forum so forgive me shortcomings
I bought a VW t5 2.5 TDI transporter with engine jerking symptoms when adding gas. An attempt to repair is practically done to overhaul the entire engine.
checked shaft and bearing shells
behind the lined block
new rings
head repair - checked tightness, planning, valve replacement, reconditioned pump injector seats.
new camshaft
all unit injectors regenerated.
driver replacement
Effect - it ignites heavily, smokes only for four cylinders, smokes white, still jerks the engine when trying to drive. All effort and costs for nothing.
I am running out of ideas.
Can anyone suggest something?

Maybe the potentiometer just got under the gas pedal?

Cranks, of course, checked or not curves ??

On Monday, the car goes to the next mechanic. it's the fourth one

Added after 2 [minutes]:

Connecting rods are also checked, they are simple. But in fact the fuel filter was not changed.

Added after 7 [minutes]:

What potentiometer are we talking about?

Falubaz1 wrote:

Ew. still the injector harness remains.

And "candles" burned to one.

filter replaced, unchanged.

I am digging out a topic with a question - has the problem been solved?