NAFTA POLE ´97 does not regulate when lighting motor

Hello friends: To be more specific, I have a VW Polo Classic Mi 1.6 and when I start it, it is not regulating, I must have it accelerated so that the engine does not stop, this lasts a few minutes, between 5 and 10 minutes, until the engine lifts a little temperature I suppose, and then it does not stop more and it goes normal.
What can it be? I await a
very grateful help.

Temperature sensor, admission butterfly if it is electronic, with a basic adjustment should be fine.

Surely you have spent or very dirty step by step