more than likely the idel speed control valve is getting stuck if the car holds it revs. as for running lumpy could be a few things plugs, lead, coil pack etc.
idel speed control valve is bolted to the underneth of the in let manifold will have a black 2 pin plug on it.

The Ka suffers really bad from the idel valve fuc*ing up and holds the revs up.

Hope this helps.