Why does the idle speed gauge needle slightly fluctuate?

[ZaneRose]

Idle speed gauge needle slight fluctuation is caused by fuel system issues or electrical circuit problems. Fuel system issues: Fuel system problems are generally caused by fuel line blockages, resulting in poor fuel supply, manifested as engine shaking, unstable idle speed, and stalling while driving; additionally, fuel pump failure can also cause engine vibration. The solution is to diagnose fuel pump issues by disconnecting fuel lines and checking fuel flow rate and volume. Electrical circuit problems: Check if the ignition timing is accurate, as abnormal ignition is usually a timing issue; additionally, malfunctioning distributors can also cause engine vibration. Solutions include checking if spark plugs are worn, whether their gaps are uniform, and if the gaps have changed.