KA24E Won't start

[fairglen21]

Okay, I have recently bought a 1990 240sx auto and it won't start. The previous owner said the car overheated and then wouldn't start back up. The battery is completely drained so I had to hook it up to another car to try and start it. When I turn the key the starter was turning the engine but besides that nothing. I am planning on replacing the fuel pump and the battery. The previous owner had just replaced the injectors, he also mentioned that he thought the radiator was bad. I have also ben told my headgasket is probably done for, I plan on replacing that as well. I just need anymore ideas as to why it's not running.

Thanks