ISX No Boost Issue

Need some help

2011 Volvo 740 with ISX (deleted)

I stopped at a red light and when I went to take off heard a squeal and at the top of the gear the truck wasn’t getting boost from turbo.

Truck is not receiving any fault codes and checks are made by Cummings software computer.

I have replaced the actuator, manifold back pressure and boost pressure sensor.

Charge air cooler has no leaks
Exhaust down pipe is clear
Manifolds are all clear
Fuel system is clear
VGT moves freely by hand on turbo
No cracks found during inspection
Checked all wires, voltages and connections

Turbo spins up to 35k RPM and actuator goes up to 90% and sets at around 70% on highway test with truck going 70-73mph

Manifold is only getting 2.9 pounds of boost.

Anything thing else to check or suggestions?

Pretty near the end of the rope on this one.

Thanks in advance

 

Will do, but how would that prevent the boost?

 

Thanks for explaining I’ll check that.
Is there any value in running the overhead?

 

Checked and no issue.