1998 Ford Taurus My 1998 Ford Taurus has intermittent start

My 1998 Ford Taurus has intermittent starting problems. When it does start it will start all day and have no issues until I let it sit over night and then it may not start for several days. I changed the fuel filter and it seemed to do the trick for a few days then, poof, same problem back to starting every second or third day and running all day no matter where I go it starts right up. I changed the spark plugs and they were quite dirty and the engine wouldn't turn over right away, but after an hour started right up and ran from noon until 10pm. I go out to start the car today and it cranks and wont start. I can hear the fuel pump engaging when I turn the key before I try to start the engine and I definitely have fuel getting to the spark plugs so I doubt that is the issue. Any help would be greatly appreciated. Thanks in advance to all who are able to assist me in troubleshooting this issue.