Not just confined to Morgans, but all modern ECU controlled petrol engines - do not just run for a few seconds or a couple of minutes. If you want to move the car out of the garage, drive it around the block or for a couple of miles.
If you stop very soon after starting the engine is stopped while still in cold start mode. Attempting a restart can mean flooded engines / excess fuel in exhaust (lambda errors) etc. and may lead to non starting...
Forget where I heard that one.
