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 

Leak-back test on injectors Marcus? 

Kind regards,

Gareth.

Thanks Gareth ..I am pretty good with mechanics but how do you do that ? 

Special kit Marcus. It’s a sort of manometer tube arrangement, best left to your trusted local diesel specialist. 

I’m not claiming this is definitely an injector issue, but these are often overlooked in favour of replacing glow plugs, which really only influence the cold starting ability in fairly cold weather. 

It sounds like you have spent a fortune on this car, and to my mind, it’s always worth investing in a couple of hours inspection by a diesel specialist ( for get main dealers or independents) before spending money on anything. 

Finding a good local diesel specialist? Ask for recommendations from local taxi owners.

Kind regards,

Gareth. 

Thanks Gareth , I know with these PD engines the diesel is fed from the tandem pump on the cam straight through channels in the head to the injectors internally and therefore there is no run off pipes to check. I have got the timing smack on now so tomorrow fingers crossed might be a lot better. I have photographed data from VCDS from earlier and the injectors look spot on..