Problem when the car encloses

Good morning;

I have a Citroën Xsara 1900 diesel, I have the car in the garage, when I start the car every morning, it starts well but since it throws a lot of smoke through the exhaust tube and it is as if it drowns a little, after about 15 seconds it stabilizes and no longer throws smoke through the exhaust pipe.

Does anyone know what can be due?

Thank you so much.
All the best.

Hello, what kind of engine you have, I mean if it is a D9-B or a wjz if you have injection Lucas or Bosch according to the injection that you have I can give you a solution

What color is the smoke made by the vehicle and what year is, to determine whether it is Cammon Rail, or normal injection thicks a little more to help you better.