I too have had the same issue of hanging revs on my Morgan 3.7 V6. Ten days ago the ECU was upgraded at Revolutions in Perth.
The Mog is a very different beast. No more hanging revs, responsive and predictable under acceleration, much easier to control coming into corners, changing down and driving through the corners. I cannot comment about the readings for fuel or speedo but will monitor the situation over the next weeks.
My first drive after the upgrade was St Fillans, Killin, Loch Tay, Crieff – no traffic, clear skies and 20+ degrees. Scottish motoring at is best. Back to France and the end of the month to do some serious mountain driving.
For anyone that is experiencing the hanging revs issue, I would definitely recommend the upgrade.
If a thing is work doing, its worth doing to excess.
