Stu,
Diagnosed when on torque of the devils rolling road. Guy next to the car noticed that fuel pressure wasn't rising when boost came in causing engine to run lean and misfire.

Agreed there's no demand at idle. Fuel pump is new bosch044. I've rewired pump following advice on the forum and checked voltage. I've also bypassed the relay and measured output direct from pump and before fuel rail which was identical at 2.2L in 30 secs from memory which seems in line with what it should be.

thanks