Hi, posted a few weeks back about my Zafira 1.8 petrol not starting, anyway it did eventually start but still struggles to start from cold, takes a good few turns of the engine before it fires into life. I have notice recently though that when you start out on a drive from cold, on dipping the clutch, the engine revs will rise up to 2500-3000 rpm for a couple of seconds and then drop back down and on finding the bite again, it is usually very 'choppy' not smooth at all. At first I thought it was just taking time to get used to it as my old car was much smoother but it seems to be getting worse. Not so bad when it's warm but awful when cold. Any ideas what this could be, would crank sensor cause these symptoms?