What are the reasons for difficult cold starts of an engine?
2 Answers
Engine cold start difficulties are caused by the following reasons: 1. Poor fuel quality: Inferior fuel has poor volatility, especially in winter when it is difficult to atomize, resulting in insufficient mixing of fuel and air in the cylinder, leading to difficult starts or even failure to start. 2. Excessive carbon deposits on valves and intake manifolds causing cold start difficulties: Carbon deposits can absorb an appropriate amount of fuel, leading to ECU judgment errors. For example, if the computer controls the injection of 100 parts of fuel-air mixture, but only 90 parts actually enter the cylinder (10 parts absorbed by carbon deposits), even if the remaining 90 parts fully combust, the required power output cannot be achieved, inevitably causing shaking. 3. Excessive carbon deposits: Carbon deposits negatively affect the normal operation of the engine. For instance, excessive carbon deposits in the combustion chamber increase the compression ratio, creating multiple hot spots that cause pre-ignition and detonation, shortening the engine's lifespan. Carbon deposits on the valve and seat surfaces can prevent the valve from sealing properly, leading to air leakage, difficult engine starts, reduced power, and other adverse phenomena such as valve erosion.
I've had several frustrating experiences with engine cold start difficulties. The main reason was an aging battery - when temperatures drop, the charge can't keep up, resulting in weak cranking. If spark plugs are worn, the ignition system fails to fire; the fuel pump struggles to supply fuel properly in cold weather, leading to clogged injectors; worn piston rings in the cylinders cause insufficient compression. I've also noticed that engine oil becomes too viscous when cold, increasing engine resistance. Additionally, low ambient temperatures cause sensors to misread data, leading to ECU miscalculations. Regular maintenance shouldn't overlook checking battery voltage and switching to winter-grade oil - it can save a lot of trouble.
