What to Do When an Electronically Injected Diesel Vehicle Emits Black Smoke?

[MaliaFitz]

It is caused by incomplete combustion due to uneven or excessive fuel supply in each cylinder or premature injection timing, among other reasons. It is recommended to seek inspection at a professional repair shop. Remove the air filter and observe the exhaust smoke color. If the black smoke emission improves, the issue is caused by severe dirt accumulation in the air filter. Cleaning it promptly should resolve the problem. Check whether the fuel supply timing is too early and adjust it if necessary. During engine operation, conduct a fuel cut-off test cylinder by cylinder. If cutting off fuel to a specific cylinder results in reduced engine speed, decreased black smoke, and weaker knocking sounds, it indicates excessive fuel supply to that cylinder.