Actually one other thing on this...why the car is still on choke first thing on a morning it runs perfect and smooth, which would make me think that the 3 injectors that are working are compensating for the one duff one?
Cos as soon as the car comes off choke and is supposed to run 'normal' it starts spluttering and really holding itself back and won't rev,sounds like it's on 3 cylinders.
So maybe then the 'good' 3 injectors arent compensating anymore and it's just running rough!?