This is really weird, been racking my brains on this one since you first posted and i'm struggling to come up with anything definite...
I'd suggest starting by checking and cleaning all your earth points, there's 3(?) on the inside of the wings and one on the gearbox. Have you checked your ignition barrel is working as it should? I'm not great with electrics so can't tell you how it should work, Cully may be able to though. Sounds like you might have a short on the loom between the ign and the ecu maybe..
I'd suggest starting by checking and cleaning all your earth points, there's 3(?) on the inside of the wings and one on the gearbox. Have you checked your ignition barrel is working as it should? I'm not great with electrics so can't tell you how it should work, Cully may be able to though. Sounds like you might have a short on the loom between the ign and the ecu maybe..