Anyway, to cut a long story three hours short, it finally transpired that, as Saturday, when we arrived, had been very hot, followed a yesterday which was more like a midwinter day in the antarctic (only a slight exaggeration here!), a vaccuum had been created in the fuel tank, and the diesel pump, which must be faulty to some extent, was not able to pull the fuel from the tank because of the vaccuum. It was solved by the use of an empty water bottle to prime the diesel pump manually.
Today we have been out and about locally and all (touch wood) has been fine.
But there is still no sun and it is still cold.
See, not such a slouch, am I!!