I didn't mention the jerks especially because I was having just the same problems as you wrote in your first post. My car is still awaiting diagnosis from a diesel specialist, the first injector which was changed/removed was assessed today by United Diesel (I posted it to them) and they said basically the piezo mechanism had worn out and it was common with high mileages - mine is 145k, what is yours?
The injector specialist has reported today that the second injector has also failed electrically, basically worn out, and needs replacing. Apparently it's common, but I am still very curious why it happened straight away after the other one was replaced. And wondering if 3 and 4 will go very soon.
One thing he clarified - the Siemens injectors do not need coding, I believe they are fitted to later vehicles around 2005/06 onwards, so not all the 1.8 TDCi Lynx engines are the same.Go to the full post