What Are the Reasons for High Engine RPM in a Car?

[OJaxson]

There are several reasons for high engine RPM in a car, including throttle assembly failure, fuel pump and fuel system issues, and air conditioning clutch slippage or damage. Below are detailed explanations and solutions: Throttle Assembly Failure: The throttle is a controllable valve that regulates the amount of air entering the engine. After entering the intake pipe, the air mixes with gasoline to form a combustible mixture, which then burns to perform work. If the throttle malfunctions, causing it to suddenly open wider, the engine RPM will abruptly increase. In this case, the throttle needs to be replaced. Fuel Pump and Fuel System Issues: Fuel injector leakage or clogging can prevent the injectors from spraying fuel as directed by the electronic control unit, resulting in a mixture that is either too rich or too lean. This can cause poor performance in individual cylinders and unstable idling. Professional repair is required in such cases. Air Conditioning Clutch Slippage or Damage: Manual transmissions, dual-clutch transmissions, and semi-automatic transmissions all use friction plate clutches to transfer engine power. If the clamping force is insufficient or the friction plates are severely worn, slippage can occur, leading to increased engine RPM. The air conditioning clutch should be replaced if it is slipping.