Ive heard of a few people had same problem... the word on the street is that clean diesel (low sulphur tree hugger stuff) is to blame it has less lubricating properties than yer good old proper heavy oil. TOP TIP put a magnet on yer screw driver and dip it into all the bleed points and see if you get filings out of em all,, if its not yer lift pump chafing,the injector pump is running on borrowed time!