My vogue was showing revs on cranking but no spark when engine heated up ---- also when started from cold would hesitate then revs would even out then ---- stop and no start after that ----- new crankshaft position sensor job done -----but my omega had LPG and every so often had to squirt carb cleaner spray into main gas line to injectors to clean up the waxy deposit left by LPG

Pretty sure most of the AEB based systems you press and hold the changeover button for about 10s will then force it to start on gas.

I don't quite get how you've got to leaky injectors. Unless you've pulled all the plugs and found that there's loads of excess fuel in the cylinders without having turned it over? But I haven't seen mention of that.

There isn't a NRV in the fuel line or fuel rail on a Thor - it's a returnless system that's pressurised by the pump and excess pressure is bled off in the pump in the tank. Different to the gems systems that have a return line and pressure regulator on the fuel rail.

Same system as my Jeep then. Sadly the Jeep already has a whole for the fuel pump and the NRV is replaceable without pulling the pump.
Hey ho.