That's high pressure pump injector cleaning/servicing/change... happens at 100-150.000 kms or sooner, if the fuel is dirty.
This is also the reason why you do not see diesel cars in Asia and Africa. Fuel is too dirty and full of sulphur, modern sophisticated diesel car high pressure pumps would die there in a few weeks.
Gasoline powered engines just burn all that crap.
well, we still call it calibration...
Small player gas stations have dirty diesel but the big ones (Shell, Petron, Caltex, etc.) are not dirty. We have low sulfur diesel fuel here and we have lots of diesel cars here. SUVs and Pick-ups sold here are all diesel except for some American SUVs. Popular diesel cars here are BMWs, Mercedes Benz, Audis, Ford, Isuzu, Mitsubishi, Toyota, etc. We don't have diesel SMALL cars here because they are more expensive than the petrol model. The market for small cars are those with limited budget and a diesel small sedan is out of the question. A Ford Focus diesel costs 1,200,000.00 pesos while the petrol model costs 900,000 pesos. A 1.2 Kia is a lot cheaper and consumes very little fuel.