What Causes Incomplete Engine Combustion?

[DelFrancisco]

Engine incomplete combustion is caused by damaged spark plugs, poor fuel quality, and excessive carbon deposits. Damaged Spark Plugs: The most common issue is damaged spark plugs. Worn spark plug electrode gaps result in insufficient ignition, leading to unburned air-fuel mixture and engine vibration during acceleration. Poor Fuel Quality: Low-quality gasoline leads to poor fuel injector atomization, causing incomplete combustion in the cylinder. It's recommended to switch to higher-octane gasoline after using up the current tank and perform a fuel system cleaning. Excessive Carbon Deposits: A dirty throttle body or carbon-clogged fuel injectors can cause throttle valve leakage or idle speed control motor jamming, resulting in high idle speed. Carbon buildup during engine operation also contributes to incomplete combustion.