Hi Chris
We checked rail pressue & map sensor readings, can't remember what they were, but was nothing that we were to worried about, have now removed injectors, checked compressions, all ok, sending off injectors for testing.
when carrying out compression test, a slight misting of oil/diesel was coming out of number 1 injector hole, might be nothing,
Like we said earlier, have a bit of a knocking noise from top end, wonder if a small end has gone and causing poor combustion?

thanks again

John