Hi all , hoping someone can help, I have a A4 B7 2.0 tdi and have a starting issue only when cold as in stood for over 8 hours. So far I have changed fuel lines, fuel filter with new T piece , fuel pump (both) tandem and lift pump.. new bosch glowplugs and checked voltage showing 6v to all .. cam timing is set correct and also changed injector seals , and even the head !! With new gaskets , stretch bolts etc ..the car pulls great when started but takes a good few turns when cold before it stutters into life and then a bit of great smoke out the back.. is there anything I could have missed? I have VAGCOM which shows no errors and the injectors show well in tolerance ..I am now at my wits end with it ..also new battery and starter motor fitted in last few months ..thanks