What Are the Reasons Why a Car Cannot Start When Cold?
1 Answers
A car is an electromechanical machine that combines fuel and electrical systems. Difficulty in cold starts during winter can be addressed by considering the following maintenance aspects: 1. Pay attention to the battery: The batteries used in cars today are generally 12V for gasoline engines and 24V for diesel engines. The battery voltage should generally not be less than 11V. For "water-filled" batteries, check the specific gravity and level of the battery fluid before winter. If the electrolyte is low, it can be replenished with distilled water or battery fluid. 2. Pay attention to the throttle body and idle valve: The throttle and idle motor are located at the front end of the engine intake manifold. During idling, air flows at high speeds (tens to hundreds of meters per second) through the throttle gap and idle motor, creating negative pressure that gradually accumulates dust. Additionally, crankcase blow-by gases and oil vapors collected from the oil vapor recovery tube are easily adsorbed by negative pressure in the throttle gap. Since this area is relatively cold, these substances can condense and form sludge. 3. Fuel pressure: To ensure normal engine startup, the residual fuel pressure in the fuel system after the engine is turned off should not be less than 2.5–3.5 kg/cm². Otherwise, insufficient pressure will prevent the fuel injectors from spraying enough fuel to ensure startup. 4. Lubricant quality: It is important to change various lubricants before winter, including engine oil, transmission oil, and brake fluid. Ordinary lubricants become more viscous in winter, reducing fluidity and increasing friction resistance during component movement, making cold starts difficult. Improper handling can lead to bearing seizure or crankshaft damage. 5. Injector coking: The fuel injector is a relatively precise component in the engine's fuel system. Its performance directly affects the engine's efficiency. 6. Engine carbon deposits: Carbon deposits in the engine are mainly caused by fuel quality, intake air quality, and lubricant quality. Using substandard fuel, lubricants, or air filters can increase engine carbon deposits.
