black smoke

[will1e]

mondeo 2002 2l tdci, lots of black smoke when accelerating
quickly but none when accelerating gradually.
i have disconnected the small black hose that fits onto the diaphram(ontop of turbocharger) and this rectified the problem, but when refitted black smoke is back, unsure if this is a problem with the diaphram or intercooler/hoses

any advice would be much apprecieted

regards
willie

[Trooper2]

A dirty air filter will cause black smoke...

[Jon GT2]

It could be lots of things but make sure everything is clean as above and possibly the egr valve is faulty.