How to troubleshoot rough idling in an Audi 80?

I've been experiencing a rough idle in my Audi 80. What could be the cause of this issue and how can I fix it?

It's possible that the air filter needs to be replaced. A dirty air filter can cause rough idling and reduced engine performance. I recommend checking and replacing the air filter if needed.

Another potential cause could be a clogged fuel filter. This can restrict the flow of fuel to the engine and cause rough idling. It's a good idea to have the fuel filter checked and replaced if necessary.

You may also want to check the spark plugs and wires. Worn out or damaged spark plugs can cause misfiring and rough idling. I suggest having these components inspected and replaced if needed.