ctrieon relay 2.0 HDI van wont start... HELP PLEASE?

Hi.
My citreon relay 2.0 HDI 52 plate wont start unless i spray easy start in the inlet manifold. once it has started it will run all day withouth any problems.
I dare not travel alone or stall the van or i'll be stuck.
what could be the problem? i have changed the glow plugs and fuel filter, still problem exsist
HELP PLEASE......Thanks