Passat Variant TDI 1.9 - Turbo disconnects.

Estimated
My Passat TDI 1.9 4 Motion between 2000 and 3000 laps of pulls, such as peat connects and disconnects. If I continue to accelerate black smoke, connect the turbo and leave with speed.
On some occasions he pulls an emission workshop alert and the turbo does not connect anymore. If I turn it off and then I go to the route and I shit it to sticks then for a short time it works well and disappears the board of the board that identifies emission problems.
Listen to talking about an admission sleeve, also of the dirty turbo but that I do not know that product in Argentina can be used to clean it, also of pressure leaks, etc.
I would appreciate someone to tell me where I can start to solve it.
Thank you very much and the excellent page.