Have just put on new head TD42 & now have an issue with 6th cylinder when bleeding all significant difference each from 1-5 but 6 has little engine change when bleed open when tightened runs without a miss for approx 15 seconds engine then reverts to a miss all points to no 6, have replaced fuel line from pump to injector 6, swapped injectors, all 6 injectors have been re-calibrated, reset valves, bleed complete system many times, all was operating fine up to pull down for head replacement please help all points to Air in line somewhere? that's the question?? Thanks Josh