i just had the car given to me. i changed the plugs and wires, distributor cap, and rotor. wouldn't even start when i first got it. now it starts and idles extremely rough. i thought maybe it was gas. i smell rotten eggs coming from the exhaust and the engine shakes. no kickdown at all. i give it gas and it doesn't seem to increase power or speed. though maybe a fuel filter and the catalytic convertor. any suggestions are appreciated.