Another issue

[Daz]

Car is acting up again... when i start up the AFR reads between 10-11 & car doesn't tick over smooth and is jumpy on low speed/low revs and has quite a bit of black smoke from exhaust but if i put my foot down it drives as normal and after about 15-20 min of driving the AFR reads between 14-15 like it should and ticks over great...was wondering with cold weather is it the auto choke causing this?