Mikethepanel

I have a 2006 2.5 525d and most mornings (not affected by the weather) when i start the car it will miss fire and run on 4 cylinders for around 10 seconds,then its clear and fine all day.
I had resistance in the injector loom so i replaced it,i just had the injectors checked and cleaned and whilst the inlet manifold was off i fitted 6 new glow plugs,now its back together there is no difference what so ever.
Plugging the diagnostic machine into the car shows no faults and flow rates are perfect,i've done a leak off test and they are all within 4-5% of each other,i now have run out of ideas.

Does anyone have any ideas or been through the same thing?

Thanks in advance