Why does the car shake when starting cold in winter?
1 Answers
Cold start shaking in cars can be attributed to the following reasons: 1. Low temperature: The engine temperature is insufficient, and both fuel and lubricant temperatures are too low. During cold starts, additional fuel injection is required to meet power demands. Larger spark plug gaps result in smaller ignition energy. Poor fuel atomization at low temperatures demands higher ignition energy. Prolonged vehicle use can enlarge spark plug gaps, reducing ignition energy and consequently affecting power performance, leading to shaking. 2. Incorrect air-fuel mixture ratio: Inaccurate fuel-air mixture ratio occurs in both open-loop and closed-loop control systems. In closed-loop controlled vehicles, the oxygen sensor's minimum operating temperature is 370°C. If the exhaust pipe temperature hasn't reached 370°C upon startup, the oxygen sensor won't function. This causes the ECU to make incorrect judgments, leading to errors in controlling the fuel-air mixture and ignition timing through actuators, thereby reducing power output and causing shaking. 3. Faulty coolant temperature sensor: The coolant temperature sensor is crucial for the ECU to determine engine operating conditions. If the engine starts at -10°C but the ECU calculates fuel injection based on 20°C conditions, the insufficient fuel quantity will naturally cause shaking.
