What are the reasons for difficult cold starts in cars?
2 Answers
The reasons for difficult cold starts are as follows: 1. Excessive carbon deposits. Especially at the throttle body. If there is too much carbon buildup at the throttle body, it affects the precision and smoothness of engine intake. In severe cases, it can even cause the throttle to stick, preventing acceleration. Cleaning is required. 2. Faulty coolant temperature sensor. Although the component is small, it can cause the engine control unit to misjudge, resulting in reduced fuel injection. This leads to insufficient engine power, making it difficult or even impossible to start the engine. 3. Insufficient fuel pressure. Fuel pressure can be measured. When the ignition is turned on without starting the engine, the fuel pressure should be around 0.3MPa; when the engine is started and idling, the fuel pump pressure should be around 0.25MPa. If the gasoline contains too much water or impurities, it can damage the fuel pump internally, leading to insufficient fuel supply. 4. Small valve clearance. After driving a certain number of kilometers, wear between the valves and the transmission mechanism can cause changes in valve clearance. If the valve clearance is too small, the car will be hard to start.
Having driven for many years, I know that the most common causes of difficulty starting a car in cold weather are battery aging and the effects of low temperatures. When it's cold, the chemical reactions in the battery slow down, significantly reducing its charge, making it unable to provide sufficient current during ignition. Engine oil becomes more viscous in low temperatures, increasing the resistance to engine rotation, making starting feel more strenuous. If the spark plugs are old or have carbon buildup, their ignition performance worsens, leading to weaker sparks in cold conditions. Additionally, gasoline doesn't atomize well in cold weather, resulting in incomplete combustion and rough starts. I remember one winter when my car wouldn't start, and after checking, I found the battery was dead. Replacing it with a new one made a big difference. I recommend checking the battery's condition before winter, switching to a suitable winter-grade engine oil (thinner viscosity), and regularly cleaning the spark plugs. Neglecting these steps not only makes starting difficult but could also damage other components, affecting daily commutes. It's best to park in a warm garage or use a cover to prevent issues at the source. If problems arise, visit a professional repair shop promptly instead of forcing a start, which could damage the engine.
