Bought myself a 1.6 driver last week, I know it has the wrong bumpers on but it will all be changing.

Basically it runs like an absolute dream when warm, but when I first start it it's also fine then 30 secs later it stalls itself and soon as I turn it back over it starts and runs fine. Sometimes it's a bit choky on cold start up.
I'm just wondering if this is a fuel filter problem? Possibly clogged up?
Any help would be appreciated thanks