Man tgm fuel pressure too high

Hi all.

I have a MAN TGM with check fuel supply, on the dash.
If you increase the idle from 600 to 650 then rev it, it doesn’t come up as a fault only comes up from idle at 600 revs. We have changed fuel filters pre filter etc had sender out, changed pressure valve from another truck. It comes up with fault 94 on delphi