Dear customer, I understand the problem you are presenting first. Allow me to explain:
Black smoke is nothing other than vaporized coal: when the fuel is hot and it does not have enough oxygen for combustion, there is a wrong explosion with a lot of fuel in the exhaust which causes the smoke that you can observe of dark gray coloration .
This means that your vehicle is not giving enough air to the system due to a problem in the turbo, or the injection system has some problems and is injecting much more fuel than air. I want to clarify that the mixture of air and fuel inside the cylinder must be stoichiometric, which means that there must be an equal amount of air with the same amount of fuel inside the cylinders.
As the diesel is basically oil, the leaks or clogged injectors cause the engine to inject more fuel than necessary, and therefore, smoke is produced.
This type of problems commonly happens due to lack of maintenance and dirts in the system. I always recommend a computer diagnosis in all the queries, as this can indicate the error codes that the computer may be generating if there is a defective component that detects a sensor, for example if you have problems in the mixture. Probably the exhaust system will detect it, or if you have a problem in the advance of the fuel injection pump can also be observed in the error code, the fuel regulator that detects a high pressure, in short estimated customer if the problem does not detect a sensor you will be able to attack the problem with greater precision and with a reduction of costs therefore I always recommend first of all to carry out a computerized diagnosis.
Dear customer, of course sometimes the scanner may not indicate anything and this is because many times the consumption occurs due to lack of maintenance therefore if this is the case what you are going to do is first replace all the filters, you must perform maintenance to the injectors and the injection pump, do not use additives to clean the fuel system on the contrary can cause more damage, finally it is not enough to review the air intake system, the acceleration body and the turbo and its pipes, since as I have explained to you, not only can it be a problem in the fuel injection but if there is little air in the system it gives the same result with the smoke in the exhaust.
Have you understood me dear customer?
Dear Customer, my goal is to give you the best advice I can and I hope that I've helped today.
If more help is needed or something is not understood, please use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service, your 5-star rating is appreciated ( should be a link to click on here or above). You can rate at any time and we can continue to work on your question as this will not close out your question. I work on delivering the best answer and help here but in some cases, it can be difficult to do without seeing the vehicle.
Best regards, Sebastian.
Thanks in advance.