Thnaks to everyone who helped regarding my solenoid and problems with my Discovery 200TDI, K Plate 1993, however one for the text books.
It was the wire from the solenoid, it had chaffed halfway along and was earthing every now and again. So new wire and shroud and hey presto my Discovery starts and stops every time.
I am soooooooooooo happy, now I need to fit my newly bought chequerplate to the sides of the doors.
Andy