I know there are other threads about this topic, but here's my recent experience.......

My '03 MCS has the same problem a lot of MINI's do, when I start it cold, it runs rough, then dies. When I restart it, it's fine, smooth as can be.

There are a lot of suggested cures for this, including waiting till the low fuel light goes out before cranking and so on; I tried them all but the one thing I didn't try was what Nate at Baron MINI had suggested - regular gas instead of premium.

Initially I scoffed at the idea, I was still running laps at Heartland and it was really hot out so I didn't want to cause any more stress on my engine with low octane fuel, but since the weather's cooled off and I'm done with track events for the year, I decided to give it a shot..........guess what? The car starts perfectly every time now! I'm on my second tank of regular and I think I can detect a slight loss of power, but it's very slight..........other than that no adverse effects that I can find.......I'm as surprised as anyone, but as they say, the proof of the pudding is in the tasting.

So, if your MINI if doing this, you might consider trying the regular gas route, plus you'll save a little money!

 

Instead of regular, try the mid-grade. You might get some of the performance back while still keeping the better starting. When I run mid-grade I have no noticeable performance or economy loss.

Of course when I expect to be doing some "spirited" driving, I fill with premium.

 

Here in NY we have a couple different "mid-grade" options. Most gas stations sell 87/89/93. However, Sunoco sells 91...or at least they did the last time I got gas there a few years ago (I haven't been back since they started adding ethanol).

 

I had that also once in awhile and I am using 93 octane 99% of the time, but never happened again by doing :

1. turning key to ignition ON for about 5 sec.
2. pump the accelerator pedal twice.

I know that the car is electronic throtle but it seems to work in my case.

 

I use to own a 2002 m3 that had the same problem , would have cold start issues. I took it into the stealership and they reflashed the ecu and the problem went away.. Might want to look into that? Just a suggestion. Steve

 

Would love to see a response to this one. I am getting my ECU reflashed on the 17th (04/2003 build Mini), and have had the same problem from the start. Was thinking it could be anything from fouled plugs or bad fuel to bad O2 sensor.

- Matt