How to troubleshoot engine failure in an Audi 80?

I recently experienced engine failure while driving my Audi 80 and I'm unsure of the cause. I would like to know the steps to troubleshoot this issue and prevent it from happening again in the future.

First, check your engine oil to see if it's low or dirty. This could indicate a leak or need for an oil change. Then, inspect the spark plugs for any buildup or wear. Additionally, check the fuel filter for clogging. Make these replacements if necessary to see if it resolves the issue.