Engine/fuel problem

Hi all, I have a slightly annoying problem with my van that I would like to fix.



Sometimes when first starting my van it will cut out after running for a few seconds, it will then not start again no matter what!

However soon as I pump the manual fuel pump until solid the van then starts again first time and will stay running with a few revs. Any ideas what needs to happen to fix, blockage, filter etc.



Thanks in advance