mark,

Wouldn't that be correct though as the FRP sensor is reporting highish voltage so the imv would react to this and up pump pressure.

I thought that the activation (ON time) for the IMV would be longer if it had a fault code set for over pressure so to force the valve open and lower pumping pressure.

I don't really know alot about diesels but i thought they had a pressure relief valve so as to return fuel back to pump incase of a high pressure state so would it be possible to measure the return flow to see if this is the case.

Liam,

With the MODIS can't you use custom setup and select only FRP sensor, IMV command so it will refresh at a faster rate, this way you can then compare live data to scope data.

thanks
lee