1.6 HDI heavy black smoke under load but not sluggish

[mini998]

Hi guys.

I have a Peugeot Partner 2008 model in the workshop .It produces a cloud black smoke under load . but Isn't sluggish at all . Plus it does not rev over 3000 RPM when it is stationary . (Could be the clutch switch kicked in???) .

So far I have done and checked these

*Air filter is pretty clean ,
*EGR working (I can see on Lexia) ,
*Map and MAF sensor swapped from a similar vehicle which is running good
*Intercooler and turbo pipes not leaking .
*Turbo wast gate arm moves and vacuum pipes are not leaking

My only guess is Injectors are over fuelling ,since I have covered pretty much everything relates to lack of air problems .

If anyone can shed a light on this before I send injectors for testing , I'd really appreciate it.

Cheers

[olegario]

Put 4 transparent pipes about 50cm lenght instead of 4 return pipes from ingectors , fix them vertically , put bolt to return pipe to the pump and start engine , you will see the difference if some ingectors leaking.