97 Passport turning over not starting
 

Ok. So I'm going nuts because we're fairly broke right now and trying to not buy the wrong part. My 97 Passport was running fine minus 1 week of rough idle while cold....(but it was real cold last week). Then one morning I went out to start it and it just cranked and cranked without starting. Acted like it was out of gas but it's not and I hear the fuel pump hum, so first I checked the filter (it was dirty so I replaced it). Cleaned the intake, cleaned the MAF sensor, changed the plugs... Tried again. No go so I tried starting fluid to see if it had spark getting to the plugs (ICM?) ...Again nothing so I removed a plug wire and checked for spark by eye. I see spark so why the hell isn't the starting fluid starting it?... At least for a second! I still feel it's a sensor or relay but not sure. There are no stored codes and it doesn't start so OBD is no help. Can't afford to go through and buy every sensor 1 by 1 right now. Please help ...