2005 1.5 d running on 3 cylinders

My customers car was running on 3 cylinders, fault coded it and there was a fault with no 3 injector, I changed it and coded it in, ran well for five mins and then back on to 3 cylinders, fault coded it again and there was a fault with no 3 cylinder again, to cut a long story short the high pressure fuel pump was worn and pumping tiney bits of metal swarf into the injector and ruining it, new fuel pump, cleaned all injector pipes, fuel rail and a further 4 new injectors and engine is running like good as new, be aware it's a costly job!