I have a 99 Mitsubishi Eclipse, it all of a sudden died. I tried to start it again and all it would do is crank over without actually starting up. Its not fuel pump. What else could be the problem?

Many things can make it stop and not restart. Even though the gas gauge reads it may be false and the car could be out of gas. The gas tank could have water in it especially if you just got gas from a station. If you think that there is water in the tank add a bottle of "heat" or tank dryer to the tank. A bad fuel filter or low fuel pressure, bad ecm(computer), bad ignition module or ignition components(coil etc), bad fuel injectors, bad crankshaft position sensor, bad ignition switch, bad relay(s) or blown fuse(s), security system/ignition key, or bad connector(s)/wiring issues. The best place to start is checking the fuses and scanning the computer for codes.