Smoking 200tdi

My 200tdi (110) has recently started emitting black smoke when driving under heavy engine loads.
It is not bad enough to fail the M.O.T. but I am puzzled by its sudden appearance.
It has a new head and re-conditioned injectors.
Mileage is 146000 miles.
Can anyone suggest why this happens and what I can do about it?


Renny

black smoke is over fueling - when was the air filter changed last ?

they all do that to a greater or lesser extent, think about tweaking the IP

Check the turbo charger hoses and the hoses between the intercooler and the inlet manifold. Any leaks upstream of the turbo would cause black smoke underload, although there is usually an accompanying noise. The hose on the inlet side of the turbo charger could be collapsing internally, restricting the air flow. Is their any loss of power?