It could be a variety of issues, I have experienced several when testing the new ECU for MMC. Does yours have the upgrade ECU?

The ECU on start up takes signals from each camshaft sensor to set the timing, these are known to go faulty, if this is the case the engine can fire up on one bank. But will usually cut out, the other issue is if the flyby wire throttle pot develops a fualt the ECU may be getting a wrong voltage reading, and may explain why it will not rev beyond 3k, however this usually results in the engine held at 2k rpm and no throttle control, limp home mode.

The best advise I can give is get Morgan rescue to recover the car to the dealer, and get them to sort it.

Adrian

Buggered Off, to a modern none leaky car, heart's still ticking