Opel corsa b 1.5 d starting problems

[bigbordo]

Hi,

i have an opel corsa b 1.5 diesel. i have problems starting it. i took it it to the auto mechanic and he first told me that the fuel is returning to the tank, so he put an non returning valve in the pipe near the engine, it did not work, next he put a pump in the pipe but also this did not work. so he told me to check the injectors pump if there is any leakage or any other problem. but it turns out that the injectors pump is OK. so now i leave my car in downhills so i can start it, once i start i do not have problems. bur when i leave it for 7 to 12 hours than it's almost impossible to start it again.
please if there is anyone who had this kind of problems give me any advice what to do or what its needed to be fixed.

cheers

[olly_s]

have you checked to make sure all 4 glow plugs work?

[bigbordo]

yes i have checked, and they are all ok.