FRST starting probs!!!!!!!

Sometimes it starts and sometimes it dont.
When it starts it runs and drives like a dream, but to do this I usually have to turn the ignition on & off to prime the fuel pump about 10 times which only works once in a while!!
I,ve got a good spark on all 4 plugs and there is fuel going up to the fuel rail. I had the injectors ultrasonically cleaned about 3 months ago and I changed the fuel filter at the same time!
When I try and start it up, it sometimes try's to fire like there ain't enough fuel gettin in which I cant understand cos there is fuel going to the rail????

ANY INFORMATION WOULD B HELPFUL AS THIS IS REALLY DOING MY HEAD IN AND IT NEEDS TO GET SORTED A.S.A.P !!!!!

Thanks.


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