What Causes a Gasoline Engine to Emit Black Smoke?

[JasmineLynn]

Car engines emit black smoke due to an overly rich air-fuel mixture leading to incomplete combustion, clogged air filters, or ignition system malfunctions. Below is a detailed analysis of specific causes: 1. Poor fuel quality: Using low-quality gasoline can result in an overly rich air-fuel mixture, causing incomplete combustion. If inferior gasoline with excessive impurities is accidentally used, combustion efficiency will significantly decrease, leading to black smoke from the exhaust pipe. 2. Clogged air filter: A blocked air filter causes an overly rich mixture, depriving the engine of sufficient oxygen and resulting in incomplete combustion, which commonly leads to black smoke emissions. 3. Ignition system failure: Issues in the car's ignition system, such as spark plug leakage, weak high voltage, or fuel injector leaks, can also cause the engine to emit black smoke.