@artg, is rite u need to get ur cars throttle body cleaned, its a tickly sort of thing connected with the accelerator wire, nd allows Air into the engine, carbon deposits get jamed over there, and its hard for the car to breath, In Balenos case, u canot c it ul have to open the jublie clip of the airfilter pipe to c it ur self (recomended to get it done by a mechanic)
also get plugs checked, ( if carbon get em cleaned, or changed) insha Allah ur problem wud solve