Sorry I have not responded sooner, have been off the boat without internet for a bit.  On the Volvo D3 – 110 you can see the round vacuum actuator attached to a rod that leads up to an eccentric or cam on the turbo.  Although Volvo calls this a variable geometry actuator, fancy terminology for a way to change the angle of the blades to change the amount of boost pressure as engine load changes.  Mine was sticking and giving an engine error code.  Virtually every company I talked with said the turbo had to be rebuilt.  I found a very helpful Volvo dealership that sent me the attached service bulletin.  I sprayed the actuator and eccentric then worked both back and forth with a screwdriver to free it up, my problem was solved.  This may be the issue you are having.