Mini One cold start problems

I have a Mini too, not sure of the year right now, but it had similar cold start problems. Hard starting, rough running until it warmed up? Could be fuel injection related. Have you tried injector cleaning?

Injector cleaning, interesting. Did you find that resolved the issue permanently, or was it a temporary fix? And which cleaning method did you use?

Cleaning helped a little bit, but the problem came back. Eventually I took it to a workshop and they replaced the injector. That fixed it for good. Maybe you should get a professional opinion?

Appreciate the insight. Ended up taking my Mini One to the shop. Turns out it was a faulty cold start injector, just as suspected. 515€ later, it's running smoothly again.