* Vacuum leak: A vacuum leak can cause the engine to run lean, which can lead to high idle speeds. Check for any loose or cracked hoses in the intake system.
* Idle air control valve (IAC valve): The IAC valve controls the amount of air that bypasses the throttle body at idle. If the IAC valve is stuck open, it can cause the engine to idle high.
* Throttle body: The throttle body controls the amount of air that flows into the engine. If the throttle body is dirty or obstructed, it can cause the engine to idle high.
* Fuel injector: A faulty fuel injector can cause the engine to run rich, which can lead to high idle speeds.
* Air filter: A dirty air filter can restrict airflow into the engine, which can cause the engine to idle high.
If you are unable to identify the cause of the high idle speed, you should take your Vanagon to a qualified mechanic for diagnosis and repair.
