After fiddling the the ECU and Ignition module connectors the other day I hadn't had any more non-start scenarios. Until about 15 minutes ago. Turning over as usual but no firing up. Then I tried what a mate suggested: disconnecting the AFM plug and trying to start then reconnecting it and trying to start it again but that didn't seem to help.
So then I thought I'd put the car in reverse and try to start it. Sure enough, the starter pushed the car back a few chugs. Then I took it out of reverse and tried to start as normal and it started!! Does this jump out and tell anyone anything about the cause of all this?