Detroit 60 bad dark smoke on speed up ramps

Hey guys,

I'm looking for advice on Detroit engine series 60 year 05 that is puffing bad dark smoke from the exaust pipe when I'm shifting up and speed to to enter the highway. Is impressive the amout of dark smoke released during this speed up...once in the highway it goes ok.
Also I felt sometimes at same situation (speeding up on ramps to enter highway) the engine kind of "Cough" faling or missing power for some seconds...pretty weird stuff.
Could it be something related with the bad fuel-injectors?
Recently I replaced the injectors tubes (or Sleeves I don't know the name exactly # Freightliner dealer, there were traces of diesel in the coolant tank and the diagnose was problems in the injector tubes.
Also this engine has this valve that make it complaint ( I don't know if it is EGR the name) in California...I don't know if it change something...

Thanks!

Bra.

 

Thanks, do you think it is covered in the Freightliner waranty for used trucks? I've that for 1year or 100k miles and turbo charger is one of the items described on it. The injector tubes job was all paid by warranty.

Apreciate your opinion on this issue.