What Causes Difficulty Starting a Cold Car but Normal Operation When Warm?

[VonVivienne]

Here are the reasons why a car may have difficulty starting when cold but operates normally when warm: 1. Reason one: Poor fuel quality. Low-quality fuel often has poor volatility, especially in winter when temperatures are low. During a cold start, the engine block temperature is low, making it difficult for the fuel to atomize. This results in fuel injected into the cylinder not mixing sufficiently with air, leading to difficulty starting or even failure to start. 2. Reason two: Excessive carbon buildup on the valves and intake manifold causes difficulty starting when cold. Since carbon deposits can absorb a certain amount of fuel, the ECU makes incorrect judgments. For example, the computer may control the injection of 100 units of fuel-air mixture, but only 90 units actually enter the cylinder (10 units are absorbed by carbon deposits). 3. Reason three: The lower the temperature, the more fuel is required for a cold start, and the presence of carbon deposits further affects whether the cold start proceeds smoothly. Carbon deposits in any part of the engine can negatively impact its normal operation.