mk4 tdi cold start judder problem

Having some cold start issues with a golf mk4 2001 tdi 100hp, possibly ATD if that's the engine code?....

Basically on cold start it judders is unresponsive and will remain that way until ignition is turned off and restarted then all is fine!!!!

It's been suggested by the dealership that it's the 3rd injector, would this be right???

Is there anything else to look at before shelling out on new injector?? temp senders, MAF's that sort of thing.

Please excuse my lack of technical knowledge.

Thanks In advance.