D5 euro4 stuttering on start up
 

D5 euro4 136kw 2006

Well maintained. New glow plugs, all filters, oil, coolant, intercooler, lifters.
Swirl flaps removed and programmed off by expert tuning company. Also EGR programmed off and cleaned.

After standing overnight and starting up it stutters and also blows quite a bit of blue smoke. What could be the problem?

Here's the video:
https://youtu.be/4rEEeX9B1mE?si=8cSvVoYv5Cx10e7k

It could be injectors. You'd have to do a leak back test to confirm all injectors are delivering the same amount of fuel.