I wish i knew about this a couple of years ago..

Ended up fitting new filter, running from fuel can and trying..

Then removing injectors and getting them tested..

Then removing coded pump and getting tested...
And so call repaired!!

Replaced pump to find it even worse>>!! £1000 later.

Then found out about switch problem and sorted it but engine was now underpowered so removed pump again and sent back to find them say there was nothing wrong with it,!! Replaced it to find it was then good.

2 months after original problem its fixed.
what a b***ache it was.. cost us a fortune for a £60 switch..
just shows the forums can save a load of hastle and money.. It was the now long gone Ilexa forum that helped me!