Hello, I hope I can offer you some assistance.
You say the car stopped suddenly without power, did the engine cut out altogether? Or did the engine just lose power and the car not go above 60 MPH, 3000 RPM?
Let me know and I'll reply as soon as I'm able to.
Thanks for your reply
The engine lost power for about a second and then stopped altogether which was embarrassing at 60 mph. When the AA mechanic tried to restart the engine to complete his diagnostics check, it fired immediately and, as he could find no reason to the contrary, I was able to drive home quite normally. The car seemed to run OK but is a bit smokey and is using more diesel than it used to. I have also noticed a very lumpy pickup from low revs when cold.