The workshop has only been open 6 weeks and so far I've seen 2 M51 powered p38's with this issue. If I was you, replace all the fuel pipes after the pump, especially the ones delivering the fuel between the injectors. They are pretty cheap at the dealer. There is one long pipe and 5 or 6 short pipes - can't remember without MicroCat. However, in true LR style, the long pipe is cheaper than the short so just get a couple of long ones and cut them carefully in half.