Rev counter racing

[Luis]

I have a fiat brava 80 sx.when u start it cold the revs go up and down really fast.When the car is heated up it stops going up and down and acts normal any ideas how to sort

 

[puntokris]

I have a fiat brava 80 sx.when u start it cold the revs go up and down really fast.When the car is heated up it stops going up and down and acts normal any ideas how to sort

Its an automatic choke, its normal, every modern car has it.