Fuel?

Vauxhall Frontera 2.2dti has an air blockage and will not start, bleed the fuel lines to injectors and after a few turns of the engine it starts but runs rough. Switch off engine leave for a few hours and the air blockage is back again and car will not start. Also changed glow plugs as inside heater light not working and the glow plug heater timer replay and the light still not working.