What are the symptoms of incorrect ignition timing?

[CaliDella]

Incorrect ignition timing manifests as unstable idle and weak acceleration. Severe cases may prevent the engine from starting, while excessively delayed ignition can cause starting difficulties or insufficient power. 1. Overly advanced ignition timing: When starting the car, the engine turns heavily (difficult to start) with a jerking sensation. At idle, the engine shakes and may stall. There is knocking sound during rapid acceleration. After starting, during operation, the engine water temperature is high and often boils over. 2. Excessively delayed ignition timing: The engine feels sluggish, weak, or even overheats. When suddenly opening the throttle, the engine speed cannot increase accordingly, and fuel consumption rises. During rapid acceleration, the exhaust pipe may sometimes backfire.