Might have sorted the car's fueling problem. After changing some pipework around and it not making much difference, I decided to try another fuel pressure regular. It was given to me free and is a know to be working 3.0 bar reg from a Vectra GSi.
Just fitted it. Didn't reset the ECU however. But took the car out. Initial thoughts were, 'it feels the same' but after driving it for a bit, (ECU had learned a bit) it did seem more competant and sounded happier under load.
Last turn and I went up a hill which it usually pulled ok at. But took it up just now and there was deffinatly a marked difference in performance. Actually felt like it was pushing me into the seat for once.
So I guess, if I reset the ECU, then it should be nice and happy.
Still no 100% convinced though. But I guess another RR session will show if the fuelings has been increased. Failing that, maybe a new fuel pump?