When mine didn't want to start, it was also quite cold, probably around 5c. although it didn't occur to me that it could be due to that as I had done an hours run first. As a matter of interest, I was also getting a problem once I'd got it going, of the throttle not closing , causing the revs to actually rise during gear changes, that got worse for the rest of the journey, finally the throttle wouldn't close at all, causing the car to accelerate and the only way I could stop was by turning off the ignition. I decided that the thottle spindle was binding slightly, so I lubed it copiously with WD40, which seemed to do the trick, though I have hardly used it since, so don't know if that was the answer.

Has this happened to anyone else? A bit worrying if it has!

Paul
[At last, I have a car I can polish]