How do I properly adjust the idle speed on my Audi 80?

I recently noticed that my Audi 80 seems to be idling too high, causing some strange vibrations. I was wondering if there is a correct procedure for adjusting the idle speed on my car to fix this issue.

To properly adjust the idle speed on your Audi 80, you will need to locate the idle control valve. This is usually found on the throttle body. Some models may have a separate idle air control valve. Once located, you can use a screwdriver to turn the adjustment screw and change the idle speed. However, be careful not to lower the speed too much as it can cause stalling or other problems.

I recommend checking for vacuum leaks as they can also cause abnormal engine idle speed. Inspect all of the vacuum hoses and connections for cracks or leaks and replace any damaged parts as necessary. Sometimes a simple replacement of a worn or damaged vacuum hose can solve the issue.

The most common reason for high idle speed on the Audi 80 is a dirty or faulty air control valve. I suggest cleaning the valve with a throttle body cleaner and if that doesn't solve the issue, consider replacing the valve altogether. This should bring the idle speed back to the normal range.