(T) lumpy running

I brought my van oct first and its been great even starting in the coldest temps.
untill a few days ago.
90% of the time its starts and runs great.
But its started to occasiinally stared to start very lumpy.wo t go properly and chugs browny colour smoke out for a short while.
it does clear up but its obvious something is not right.

Im a window cleaner so its a lot of stop.starting short distances.
avereaging once a day its doing this now at totally random times.
Hardly ever from cold start at begining of the day.
any ideas please
thanks

Year, model, engine

10 plate.swb ducato 100 multijet.
not sure about engine will have dig out my paperwork.should say on that or log book?

Stop start, town driving, don't buy an all fancy dancing Diesel with all the emissions fitted. Finally agree with this one after buying a Panda that was used for town running. Choaked innarts, it was almost solid with the black stuff.
Egr on scan showed working ok but all pipework to and frow was solid.
Ran ruff, hunted, like injector problem but wasn't.
Smoked on starting and got worse as weeks went by.
No cutting out though.
Sounds like yours..
How about an Exorcism..

Got that info yet?

look on the Transit forums. It is the same 2.2 engine.