Removed the FPR - it looked spotlessly clean. Don't think there's much else I could have checked.
Disconnected the fuel pressure switch/sensor on the common rail as I heard that if the fuel pressure can't be measured, the ECU will use the "default" ones. My thinking was that if the rail pressure was low, then with the default ones, the ECU would open up the injectors. No difference - the only that did is put the EML light on

Still waiting for PP2000.
This is really annoying, as the car is otherwise fine and once started, will keep going all day long (and start) with the usual power. If I can't get this sorted easily and cheaply, this will be the death of it.
