If I was a betting man I'd say it's not your timing chain.
Has happened to me before twice on two Alfa's, first time it was a tear in the flexi pipe leading to the throttle body, second time was a faulty MAF.
Does the car move up through the revs ok? , judging from what you've said my guess is the MAF is playing up. Easy couple of thing's to check as below.
Open the bonnet and check all around the air flow piping leading to the throttle body , look for any air escaping or any tears, small rips in the piping...if you find one that's your issue. If not the MAF sensor is next , unplug it and see if it makes any difference to the engine running , if it does that's your issue. I'd go and buy an OBD2 scanner if the car is 2001 or older and read the code yourself, if it throws up P1172 - P1178 it's an airflow issue anyway and will be something along that line.
Jacekowski - This is an owners forum where people come on looking for help and guidance from other members, if you don't have any of that or want to be a dick to people, avoid posting at all. Bad form man.