have you had the duel mass flywheel/starter motor changed?

When the duel mass flywheel starts to ware it chucks metal filing into the start motor and slowly starts to seize it.

What then happens is the starter motor starts to draw more current that is normal, As the injectors take so much power to open, they can't open as they should thus taking longer to start.

The gauges are doing what they are doing as the starter motor robs all the power.

As for it only being from stone cold, metal expands when hot so the startmoter will be less seize when hot!

take the starter motor out and bang the eng that goes it the gearbox on the floor.

if metal filing come out, theres your problem