Buick/Olds: dying, fly wheel, oxygen sensor

Question
I have a 1991 buick regal limited and a couple months ago I was on my way to the store and when I got back out to the car and went to start it it did start but it was coughing and choking so I floored the gas hoping it would spit it out and the RPM's started dropping and then it died.  It wouldnt start back up so I waited about 30 minutes and it started back up.  It is still doing this.  My boyfriend asked you about this already and the expert thought maybe it was the oxygen sensor so we replaced it and that wasn't it. The person I bought it from said he found yards of yarn wrapped around the fly wheel and said he fixed the problem.  He didnt.  The car drives just fine any other time.  It hasnt died any other way. So I am wondering if you have any more ideas.  I appreciate your help.

                         Thank You
                            Charity Phillips

Answer
First we need to clarify something. I am NOT the owner of this website, I am ONLY a volunteer and it was NOT I who suggested that you replace the oxygen sensor.

You will first have to determine if your problem is a fuel problem or an ignition problem. Once you get this established then we can proceed.

thomas