I concluded that as the SKIM gave an error message only with this problem I would look at the other error codes. I had one which was low pressure at the injection manifold. This got me thinking.
A few weeks ago the engine died when going up a hill as it revved up but restarted. It died again as I accelerated off a roundabout but restarted OK. This was the same fault I have on my old GV when the fuel filters needed changing. I would run fine but die at 2500/3000 revs every time. I decided to leave it for the moment.
Remembering this I put in 20l of diesel and it seemed to start more easily. I then filled up the tank and the problems have gone away. I haven't run the tank down to the level I had the problem but that will be the final test and ill post the result if changing the fuel filters will sort it out. I read somewhere that there is no scavenger pump on the 2.8CRD just a lift pump so I wonder if the fuel flows bank when low and cant get past a clogged filter fast enough to start.