I'l call this a fix although not so sure. I fitted a new electric in tank pump. I tested the pump in a container before fitting and it made 1.6 bar dead headed.

I fitted the pump and now have 1.1 bar on the supply circuit and 11.5 bar at 4000rpm at the tandem which is correct I believe.

The car now starts fine, which was the original problem but I still think there is too much pressure on the supply circuit. I would rather see a value of around 0.70 bar or even less

Angus, thanks for the offer of docs and Joe, also thanks to Christy Doyle for the call and best wishes to everyone for Christmas and new year.

Jim