...... and I wouldn't simply swallow the 'It's the Ecu' diagnosis, especially if it's given remotely. A new ecu is the pinnacle of scatterbomb parts replacement and I doubt it will actually solve the problem.
Just a quick update on this saga. Took the Omega to my 'ECU definitely' man. The fault
was as he diagnosed - the ECU was goosed. Apparantly, new ones are on back order at VX, and are well over a grand, plus VAT when available.
He has previously successfully wiped and reprogrammed used 2.2's and 3.2's ECUs in the past, but he struggled with the used 2.6 ECU I got for some reason. Fortunately he managed to find a brand new boxed GM unit 'gathering dust' at a fraction of the cost, programmed it, and now the car is starting and running as sweet as a nut - like the proverbial sewing machine
Seems like the intermittant non starting issues, that had got progressively worse since the start of this saga, were nothing other than the start of the ECU failing, and throwing red herrings into the mix. Fortunately other informative topics on here with similar starting issues also pointed towards the ECU failing.
Experience in a particular field is always invaluable in diagnosing symptoms relative to an actual fault, and the recommendation of this particular auto electrician above all others by other VX technicians being a good indication of his ability....