cold start problems but not when warm

[jkfcomputers]

Hi all im new here and are the very proud owner of a fiat stilo 1.6 active sport in black,
i have just purchased the car two weeks ago and are very very happy with it apart from one problem
When cold it takes me ages to start but when its warm it starts straight away have the rpm sensor changed but its still the same garage cant seem to find my problem to my dismay may any help would be really appreciated

chris