Pipe contraction

Hi, can anyone diagnose the problem i'm having.

I have a 1999 disco TD5, i broke down last week after losing power.To cut a long story short i was told the turbocharger had gone which i replaced today. The problem has not gone away, there is absolutely no power until i get to about 2000 revs, then it feels like the turbo kicks in, there is also lots of black smoke.
The only other thing i've noticed is that the pipe leading from the ERG valve is completely contracted as though desperate for air until i turn of the engine.
The loss of power seems to get worse and more frequent the longer it runs.
Any suggestions would help because i really am at a loss

Thanks :alien:

The inner lining of the pipe has collapsed and is blocking the airflow. replace the pipe.

Ok, thanks will give it a go

Or squirrels are nesting ...