1995 Citroen zx 1.9 diesel will not start?

I started my 1995 citroen zx after it had sat for a few days in the snow from the recent cold weather. It started but began to cough and splutter. I thought there may be water present in the fuel system and opened the bleed screw and pumped it manually. There was no evidence of water though. After the bleeding operation it started but the engine did not stay running for more than a few seconds. Now it does not start at all. What could be the problem. Is it possible that air has inadverdantly entered the fuel system when I was trying to bleed the water out of the system? How do I remove the air from the fuel system.