So i got my 95 eldorado about 3 years ago. it drove fine when i first got it, but then one day after i gave it an oil change; i went to start and it just started surging and idling rough. From that point on it has been hard to start, once its started it idles and drives rough. Besides those problems it is hard to track the problem since it doesnt do it all the time. I've replaced the fuel filter and replaced the spark plugs. i asked a few guys at a local shop and the said it could be a vacuum leak but if that was the case it would be doing it all the time.