Poor idle on petrol startup

[tkn]

ONLY when starting cold, and ONLY on petrol it starts and then idles up and down through the rev range (like it's confused! lol) and spits out a bit of black smoke as though it's running rich. Only does this till it's warm (literally a minute or so) then idles beautifully and no smoke whatsoever.

Sounds as though it might be temperature related - my first thought is choke, but it looks like you are fuel injected?

Depending on how your gas is set up, the choke might not affect gas operation. But if injected I can offer nothing, except check the coolant temperature sensor.

What happens when idling rough if you give it a 'blip' of accelerator?