Engine Cuts Off When Crancking

Hi I have a diesel 2004 Ford Fiesta (90K miles), which sometimes fails to start when it gets cold outside. I think I need some help form a Ford mechanic or somebody who knows these cars inside out.

The issue only happens when temperature drops to about 5C and lower. It doesn't happen every time, sometimes engine will start right away, sometimes it won't. This never seems to happen during warm seasons.

Here is what happens if it has been a frosty night - I get into the car, turn the key and wait for about 10 seconds to let glow plugs heat up. Next I cranck the engine, but after about 1 second it just cuts off. I have to turn the ignition off and repeat the process. It can take anywhere between 2 - 4 attempts before the engine will start.

I never see glow plug light come on, even during winter at -10C. My initial thought was this had something to do with glow plugs, but if the glow plugs were bad, I would still be able to cranck the engine for quite some time, it just wouldn't be able to start. Something makes the engine cut off only after 1 second.

- The car has a brand new battery, same spec as the original

- All injector seals were replaced (some of them were leaking)

- Fuel filter was replaced

Glow plugs have not been replaced, because I don't have any issues starting the car during warm seasons, so I'm thinking glow plugs are OK.

I am a bit lost, because I can never reproduce the problem when I go to my garage. Any ideas what this could be??

Cheers.