Running rougher than a bag of spanners, using loads of fuel

Hello all!

After a bit of time off abroad I'm back in the UK and now I'm having a few running issues with the cabby.

Cold starts are bad, the engine will fire and start no problems, seems like the auto choke is working but then after 20 seconds the engines loses it's revs and tries to die, I have to handbrake it at junctions and rev the car to keep it from stalling.  She runs really rough - like only 3 cylinders are working but after a couple of minutes the engine settles down and seems to be fine.  I can smell fuel quite badly too.

I drive literally 10 miles to work and it's costing me a tenner in fuel each day.  My M3 didn't even use fuel like this!
Any ideas peeps?

have a read of the 2e2 faq thread, my guess would be coolant channel o'ring