[sicnarf]

Start by checking all pipes and vaccum lines for air leaks. Clean idle engine. Your car has been serviced recently? If not start with that. Oil, filter, sparkplugs, airfilter , gasfilter and fuel relay.

[bönan]

I had that exact problem and my mass air flow sensor was bad. I replaced it and the car has been fine since. It should give you an fault code to read.