The air cleaner didn't work loose as well over the bump did it?
Second thought - the ECU has tried to compensate - disconnect battery for a while then reconnect, then try engine again.
Thanks Richard
The air cleaner (the Morgan stage 1 one) is still in place
I tried disconnecting the battery for a while but no change. It is also "pinking" (stones in the mudguards noise) at high revs, which I haven't heard since the stage 1 kit was fitted. So I guess there is a fuelling issue linked to the ECU as you suggested.
