What Causes a Sudden Drop in Engine RPM?

[Heidi]

Engine RPM suddenly drops for the following reasons: Fuel system malfunction: Generally, when the fuel system is blocked, it may cause a drop in speed. Insufficient engine power: The engine itself lacks sufficient power output, with the output power being lower than the rated power, resulting in too low RPM. Another reason could be issues with the main pump. Low fuel quality: Using fuel of poor quality or with high water content can lead to insufficient engine power, causing a drop in speed. Intake system malfunction: Leaks or blockages in the intake system can result in insufficient air supply to the engine, leading to incomplete fuel combustion, which manifests as a drop in speed and black smoke emissions. Large solenoid valve gap: An excessively large solenoid valve gap can cause insufficient fuel supply, thereby leading to a drop in engine speed.