azas2 1/2/2012It may be the throttle position sensor or the Additional air valve
Jimm 1/2/2012Several possibilities; faulty fuel injectors, faulty air / fuel ratio (mixture), faulty spark plug cables (wires), faulty O2 sensor, among several ideas - plus those listed already.
Steve 4/13/2012Sounds like you may have an air leak. These engines run full manifold vacuum in the crankcase and will not tolerate ANY air leaking in. Make sure your oil filler cap is on straight and sealed down tight and that the rubber washer on it is still soft enough to dig your thumbnail into. Make sure your oil dipstick is FULLY seated. Look at your rubber boot at the bottom of the intake manifold, the bellows cannot be torn nor the metal clamps loose. Finally make sure the valve cover gasket is in good condition and both of the surfaces it touches when assembled are razor-cleaned and free of ALL old gasket material.