What causes the Audi 80's high engine idle speed?

I recently purchased a used Audi 80 and noticed that the engine idle speed is quite high, even after it has warmed up. Is this normal or is there an underlying issue I should address?

The Audi 80 is equipped with an automatic idle speed control valve that can get stuck in the open position. I suggest checking and cleaning the valve to see if that helps lower the idle speed.

A worn out throttle linkage or a vacuum leak can also cause high engine idle speed. Have a mechanic check these components and make any necessary repairs.

One possible cause of high idle speed in the Audi 80 is a dirty or faulty idle air control valve. Try cleaning or replacing the valve to see if that resolves the issue.