What Causes Black Smoke During Cold Start?
1 Answers
The reason for black smoke during cold start is: incomplete combustion during engine operation, overly rich air-fuel mixture, meaning the excess air coefficient in the cylinder is too small. Some fuel decomposes into free carbon under high temperature and is expelled from the exhaust pipe, forming black smoke. Precautions for cold start are: 1. The idling warm-up time should not be too long, 30 seconds to 1 minute is sufficient; 2. Before cold start, keep the vehicle in the powered-on state for a few seconds to allow the control system to complete self-check and the fuel pump to establish normal working pressure; 3. Avoid high-speed driving. Drive normally only after the transmission system, steering system, brake system, and differential suspension reach their normal operating temperatures.