I'll admit that I'm not really that informed when it comes to injectors (re-jet the carburator maybe but, alas... those days are gone...), but it seems like dirty injector(s) would cause the rough idle all the time. I only have the problem for the first 5 miles or so after I put gas in her. It happens every time, and doesn't seem related to brand of gas.
Originally Posted by beden1
Have you had your fuel injectors checked? They may need to be cleaned as the reason for your idle issue.
2008 M3 Sedan Alpine White / Fox Red