Sounds like a restricted or blocked boost signal from the manifold to the ALDA. When the turbo starts pumping more air more fuel is needed, without the boost signal the engine does not getthe proportionally more fuel that it needs. The result is like having a normally aspirated diesel! Pretty slow sluggish behavior especially a lack of acceleration under load.

Disconnect the hose from the manifold or IP and if there is no difference, that is probably the problem. The cure is cleaning the accumulated carbon/oil from the fittings, hose, and overboost switch. A good signal to the ALDA will result in the characteristic surge of power when the turbo spools up around 2000 RPMs, hang on! Good Luck!