Hello Fellow Mini Owners,
I am the (mostly) happy owner of a 2009 MINI S Convertible. About six weeks ago, my 8 month old car with only 7,400 miles on it, began starting and idling rough. When I took it back to the dealer for diagnoses of the problem, I got the "you need to only use "Top Tier" premium gas" story and was sent away with nothing more than a bad attitude and a free car wash. Well, I switched to only top tier gas only to have additional problems occur including backfires, misfires, and the "half power" engine light come on sporadically then consistently at start up. I took the car to a different MINI dealer that ultimately diagnosed a bad high pressure fuel pump. The component was replaced and I'm now back to happy motoring again. I want to thank my fellow MINI owners on this site for sharing similar problems as this is what helped me do some additional research to gain enough information to speak with knowledge and insight into the problem when I took it to the second dealer.

 

If the dealer would only give me my car back.................................. Hopefully I can say the same! Had the exact same problem, same crappy story from the dealer, and hopefully the same, helpful fix in the end. Supposed to be replacing the HPFP but it has taken a week.