What to Do When a Diesel Vehicle Emits Black Smoke?

[DeChase]

Diesel vehicle emitting black smoke requires checking or replacing the air filter, cleaning the fuel system or adding fuel cleaner, and inspecting the fuel injectors. Excessive black smoke from diesel engine exhaust is mostly caused by incomplete combustion due to uneven or excessive fuel supply to each cylinder, insufficient air intake, poor atomization, or premature injection timing. Here are the solutions for diesel vehicles emitting black smoke: 1. Remove the air filter and observe the exhaust color. If the black smoke condition improves, the fault is caused by severe contamination of the air filter; 2. Check if the fuel supply timing is too early, and adjust if necessary; 3. During engine operation, conduct a cylinder-by-cylinder fuel cut-off test. When a cylinder is cut off, if the engine speed decreases, black smoke significantly reduces, and knocking sounds weaken or disappear, it indicates excessive fuel supply to that cylinder.