Re: 96 Contour problems
I have a 1997 Contour Sport (2.0L), and roughly two years ago my Contour started acting up, and I assumed I was having an issue with "missing" on one of the cylinders. I took it to my mechanic the next day (it did start and run about two miles to my mechanic's shop), and it turns out I had a bad coil. Not sure how many my Contour has (I assume two), but replacing the bad coil got it running right again.
Now, the time I had oil literally "all over" my spark plugs (in 2006 with 88k), that was a bad head gasket. In regards to the fuel filter releasing that black sludge, I know my Contour has twice in the past thrown a bad Mass Airflow Sensor code, and the only thing it really needed was a new fuel filter. Go figure! My advice is to replace the fuel filter often. Ford recommends fuel filter replacement every 30k... even though that's probably even earlier than you would need to worry about it on most Fords, or any car, I would lean towards changing the fuel filter more often, than not. Just a suggestion there.
I have no idea if any of this can or will help ya, just some insights as to what I've had to do in the past. If you ever have any other questions about the Contour or problems that I have had, etc., feel free to ask! :)