Turns over but won't start
 

Hello .I have a 2007 Mini Cooper S,. I just got it a week ago and it has been starting and running good until this morning. When attempting to start it sounds like it just about starts but does and just keeps turning. The tax shows slight movement. I only discovered this morning that I was supposed to be using 91 gas . Any ideas?

it could be anything. check compression, try quick starter fluid/spray, check spark plugs, check the high pressure fuel pump, check the fuse box for water damage specially if you have a sunroof...etc

Check if you’re getting spark. Is it getting fuel? Remove a spark plug and look down the port while someone tries to start it. Do that for all 4. You should see fuel spray.