Technical Power loss/cutting out mystery

[billionaire]

Can anyone help with this?
I recently bought an 02 seic 18,000 miles, minted, 1.1, full history. It drove great on test drive, I've since learned cos it was cold, but when it comes off choke it occasionally loses power, as if it is out of gas, then picks up again. Also, again when it is warm, it starts stuttering on idle, sometimes to the point of cutting out. I know its not an electrical problem as all recently replaced. As I'm new to car I don't know if there is a common air/fuel filter/pump problem. I have noticed that on acceleration I can hear a noise from the front that sounds like air being sucked in. Is this usual? problem seems to be getting worse so any help would be appreciated.
Thanks

 

[rallycinq]

Yours is MPi so can be read.

Start there, although I would suspect O2 sensor failure, as they only work when hot not cold.

Also check the induction system for leaks.

ps You don't have a choke.

Cheers

SPD