thanks, I got the 4.4L / min figures from FSE website, but it also said this was at 3 bar. I've got a fuel pressure gauge on now and issue is fuel pressure not increasing inline with turbo pressure causing weak running / misfire. Have checked regulator and vacuum connections.

All I've done before to check the pump is to take the pipe from the fuel rail into a measuring jug, bypass the relay and time for 30 secs ..is this best way and does it take into account 'on demand'?

thanks,