Why does my Audi 80's engine keep revving up and down?

I have noticed that when I am driving my Audi 80, the engine seems to rev up and down without me pressing on the gas pedal. What could be causing this issue and how can I fix it?

It sounds like you may have a problem with your throttle position sensor. This can cause the engine to fluctuate without driver input. I would recommend bringing your car to a mechanic to have them diagnose and replace the sensor if necessary.

One possible cause for this issue could be a dirty or faulty mass air flow sensor. This can cause incorrect readings and lead to engine revving. You may want to try cleaning the sensor first and if that does not fix the problem, consider replacing it.

Your car may be experiencing issues with its idle control valve. This valve controls the idle speed of the engine and when it malfunctions, it can cause the engine to rev up and down. I would suggest having a mechanic check and potentially replace the valve.