Golf mk5 2.0 gt tdi starting fault (injector 1)

[GAZ86]

Hi wondering if someone could help me, I have a mk5 gt tdi 170bhp, last few weeks I have had problems with starting, it struggles to start and judders for a minute when started. On vcds I have a fault for injector 1 yet it passes all tests so don't think it's that. Thinking its maybe the loom or the in tank pump. Anyone else had this fault or got any suggestions? Thanks