what would make a 1996 ford mustang turn over but will not start?
Charge up the battery. Spray some starting fluid in the intake. Spin the engine. If it fires, you need to look at the fuel system.
Like tenspeed said, but it's probably a failed fuel pump. Do you hear the pump buzzing when you turn the key but don't crank the car over?
Like ten speed and tom stated could be a fuel problem. Have the ignition system checked out as well. Check the fuel rails for pressure, it could be as simple as a fuel filter that is plugged, or a bad fuel relay.
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