Why does my RPM stay high?

High RPM can be attributed to various factors in an automotive engine. One of the primary reasons is the disruption of the throttle valve. When the throttle valve malfunctions, it can cause the engine to rev unexpectedly, leading to high RPM levels.

Another common cause of high RPM is the malfunction of the Idle Speed Control (ISC) system. This system is responsible for maintaining a stable idle speed in the engine. When it fails, the engine may not idle smoothly, resulting in RPM fluctuations.

Clogged injectors can also contribute to high RPM issues. Injectors are responsible for delivering fuel to the engine. When they become clogged, the fuel delivery may be interrupted, causing the engine to run richer or leaner than it should. This imbalance can lead to high RPM levels.

Damage to the ECT (Engine Coolant Temperature) sensor unit can also cause high RPM. The ECT sensor monitors the engine's coolant temperature and sends signals to the engine control unit (ECU). If the sensor is damaged, it may send incorrect signals, causing the ECU to adjust the engine's operation incorrectly, leading to high RPM.

Disruption of the ignition coil is another potential cause of high RPM. The ignition coil is responsible for generating the high-voltage spark needed to ignite the fuel in the engine. If the ignition coil fails, the spark may be weak or intermittent, causing the engine to misfire and run at high RPM.