Hi I wonder if anyone can help I've got a misfire at around 2800-3500rpm on my disco 300tdi it's a 2000 year so running fly by wire set up ive changed all filters lift pump leak off pipes etc but still doing the same almost like its cutting out then coming back to life diagnostics are not picking anything up but still doing it ive even run a separate fuel supply straight to new lift pump but again same fault ..... Any ideas ?? HELP ...