When the engine produces black smoke, some operators do not know how to judge which parts have faults. This page will introduce the causes of black smoke, fault causes and how to diagnose and eliminate them.
1. Causes of black smoke
Due to the incomplete combustion of diesel, the unburned carbon forms free carbon, which is suspended in the fuel gas and discharged with the exhaust gas, which becomes black smoke.
2. Fault cause
(1) The air filter is blocked and the air inlet resistance is too large.
(2) The fuel supply of the fuel injection pump is too much or the fuel supply of each cylinder is uneven, and the density is too high.
(3) Intercooler blocked.
(4) Poor fuel injection of fuel injector.
(5) Low cylinder pressure.
(6) Poor diesel quality
(7) Insufficient cylinder pressure.
3. Diagnosis and troubleshooting of black smoke:
(1) Remove the air filter, check and clean the intercooler. If the black smoke from the diesel engine disappears, it means that the air filter is too dirty and should be cleaned.
(2) If the air filter is good and the diesel engine emits black smoke when idling, it indicates that the oil supply under idling condition is too large. Check the fuel injection pump.
(3) If the fuel supply of the fuel injection pump is good, check the fuel supply timing of the fuel injection pump.
(4) If the oil supply timing is correct, the single cylinder oil cut-off method can be used to check the working condition of each cylinder. If the rotation change of a cylinder is not obvious after the oil is cut off and the black smoke disappears, it indicates that the cylinder is not working well. It may be that the oil supply of the slave cylinder is too large, the spray quality of the injector is poor or the cylinder pressure is too low. It shall be eliminated after diagnosis.
(5) If there are no problems above, it may be that the diesel quality is too poor, resulting in incomplete combustion, and the diesel shall be replaced.
