95 cadillac sedan deville

hopefully someone can help me out. My car just stopped working one day at 4 in the morning went to go drop of my cousin i was going home i stopped at a stop sign and my car just died that was like a month ago. my starter and battery didnt work no more so i changed that a week and a half a go and i tried cranking it up but did not turn on. this past saturday i got home from work and i decided to try to crank it and it cranked i test drove and it was fine then took my sis somewhere and i was going home and my car just stopped on a light and it wont start no more. i tried putting starting fluid on the throttle body and turn the key but it wont start it turns but it wont start. i hear the fuel pump working and fuel filter was changed last year and i clean my fuel system with that fuel system cleaner and spark plugs were changed like 2 years ago about 10,000 miles ago or less
any ideas what might be wrong

Check the stored computer codes first. Press and hold the "off" and "warmer up" buttons on the climate control panel at the same time for about 5 seconds. Do this with the ignition key in run, or with the engine running if it will! It will go into diagnostics mode and display the codes on the bottom of the dash. Let me know what codes come up, and I'll try and help you out. After you have written down the codes, just turn the ignition to off.
Right now, it sounds like an ignition problem, but the codes should narrow it down.