well first off your description of the problem is vague at best.... didnt you just get this car?
If so, do yourself a favor and give it a cheapy tune up.
Plugs, fuel filter, clean the maf, fresh dist. cap and rotor.
Once you get those things in, see how it runs.
Oh yeah and pull codes.... there may not be anything there, but you never know. Not all codes will give a check engine light.