During cold stars the engine surges and the waste gate builds and then dumps until warm.
If you hold the break on it will not surge?

Your answer may be wastegate-related:

The most common reason is that all of the compressed charge air is not getting to the engine. It's leaking somewhere, causing a fuel-rich condition. Check the hose between the intercooler and the intake manifold. Also, check the hose between the turbo and the intercooler.

The wastegate's normal job is to keep boost pressure from becoming excessive. However, the following can happen:

. Valve can stick open--there may be a boost control solenoid.

. Seal for the valve can crack.

. Spring can break.

. Turbo can fail. It may not be spinning. Turbo failure is much greater on trucks that don't use full-synthetic diesel HDEO.

. Wastegate is not receiving the correct pulsed pressure from the computer.