What Factors Determine the Ignition Advance Angle?
2 Answers
Engine ignition advance angle is determined by factors such as engine speed, load, and fuel type. The most significant factors affecting the ignition advance are speed and the combustion rate of the air-fuel mixture. The ignition advance angle refers to the spark plug firing before the piston reaches the top dead center of the compression stroke, igniting the combustible air-fuel mixture in the combustion chamber. Below is relevant information: 1. The functions of the ignition advance angle are: (1) Ensuring the energy generated by the combustible air-fuel mixture is effectively utilized. (2) Improving the engine's output power. 2. Methods to verify the ignition advance angle: (1) Start the engine and repeatedly press the accelerator pedal. If the engine feels powerful and there are no abnormal knocking sounds, it indicates the ignition advance angle is appropriate. (2) Increase the engine speed and confirm the ignition advance angle by observing the movement direction of the timing marks.
I've always thought that ignition timing is mainly influenced by engine speed. When driving fast, the spark plug must fire earlier to ensure complete combustion. When the engine is under heavy load, such as when fully loaded or climbing a slope, the ECU will appropriately delay ignition to prevent overheating and knocking. Temperature itself is also crucial—when the engine is hot, timing shouldn't be too advanced, while a cold start requires some preheating. Higher fuel octane ratings allow for greater ignition advance, so choosing the right gasoline grade is important. The Electronic Control Unit (ECU) adjusts in real-time based on sensors, such as the knock sensor monitoring abnormal vibrations and the throttle position sensor indicating pedal depth. In short, getting the timing right makes the engine run quietly and efficiently. After driving for so many years, I believe regular checks of these parameters are essential to maintain perfect vehicle condition.
