Why is it difficult to start a cold car but normal when the car is warm?

[Jade]

It may be due to a damaged water temperature sensor, causing the ECU to use preset values stored in memory, resulting in difficulty starting the cold engine. Solutions are as follows: 1. Check if the piston rings are burning oil. 2. Ensure the battery has sufficient charge. 3. Verify if the engine oil has been changed on time. 4. If the engine is too cold, park the car in a warmer place or pour some hot water over the engine before starting. If the spark plugs are too cold and cannot reach the ignition temperature, the car won't start. Wait until the engine warms up and the overall temperature rises before attempting to start again. Below are common faults in electronically controlled gasoline injection engines: 1. Failure to start or difficulty starting: Symptoms of failure to start may include no response when turning the ignition key, the starter making noise but not turning, the starter turning but failing to engage the engine, or the engine being turned by the starter but not starting. Difficulty starting may manifest as slow engine rotation or uneven engine sounds during rotation. Starting issues may occur in freezing or extremely hot weather, at normal temperatures, or when the car is cold but starts normally when warm. 2. Poor idle operation: Symptoms include unstable idling with engine shaking, idling speed exceeding the upper limit, idling speed below the lower limit, or rough idling. These issues may be related to faulty or malfunctioning components such as fuel injectors, oxygen sensors, air flow sensors, or exhaust gas recirculation valves, as well as poor connections in control circuits or vacuum lines. 3. Excessive fuel consumption: Common causes include clogged air filters restricting airflow, coolant temperature being too high or too low, incorrect ignition timing, valve timing, or idle adjustment, wear and tear of engine components, low cylinder pressure, leaks in fuel or air lines and connections, or faults in sensors, connectors, wiring, the ECU, or its connectors in the electronic control system. 4. Excessive oil consumption: Mainly caused by excessive wear of engine crankshaft and connecting rod mechanisms, valve system components, or oil seal failure leading to oil burning or leaks. 5. Abnormal exhaust smoke: Includes black smoke, white smoke, and blue smoke. Black smoke indicates a rich fuel mixture, related to defects in the fuel supply, valve system, mechanical components, or electronic control system. White smoke suggests high water content in the fuel. Blue smoke indicates oil burning.