Ok, so the running problems now solved, time to crack on with the starting issue.
Basically, when you try to start it you can hear the starter motor try to turn over but it doesn't turn over. If you try for long enough sometimes it does turn over but quickly dies. But more often than not it won't even start.
If however you keep your foot on the accelerator 9/10 it does start, but, the revs sit at around 800-950 rpm (foot still planted to the floor) for a few seconds before the car revs. On starting a big puff of white smoke comes out and then goes, only get a single puff never a stream of smoke. The garage where I work says it sounds like when it starts the cylinders are delayed (think they said it starts on 2 cylinders then a 3rd followed by the 4th).
Also, until the engine is warm the car idles rough and you can feel a vibration through the car (juddering), nothing major but its definitely there. This seems to go, or at least is less noticeable when the engine is warm.
If the car is not left for too long between starts then it is easier to start, but you still need to press on the accelerator most of the time.
I have VCDS Lite (Registered), are there any blocks I can log whilst starting the car to see if it is a) requesting the right amount of fuel (without accelerator pressed) and if so, are the injectors getting the right amount at start (has been suggested maybe air is getting in the fuel system and pressing the accelerator is possibly shifting this quick enough to allow it to start). Maybe there is a block to measure cranking (although I have replaced the crank sensor it was with a second hand one, could this cause it?)
Sorry bit of a long and hard to read post, hope it makes some sense
