Reasons for Fluctuating Idle Speed in Electronic Fuel Injection Diesel Vehicles

[VonGavin]

Reasons for fluctuating idle speed in electronic fuel injection diesel vehicles are as follows:1. Excessive dirt in throttle body and intake ports: Too much dirt can alter the cross-sectional area of the air passage, preventing the control unit from accurately controlling the air intake, resulting in either too rich or too lean mixture and abnormal combustion.2. Various gases entering the manifold: Air, fuel vapor, and combustion exhaust that should not enter the manifold or various valves leak into the intake manifold, causing the mixture to be too rich or too lean and leading to abnormal engine combustion.3. Control unit receiving incorrect signals: Issuing incorrect commands, resulting in inaccurate idle speed air intake control, engine operational issues, which are the causes of unstable idle speed.