89' 240 won't start.

[240irv]

My 89' 240sx will not start. I wen't through the usual checklist and found the battery was dead. I replaced the battery and everything electrical in the car worked. I then attempted to start and the engine turned over but never actually started. After a few tries about 30 minutes in between each one I gave up. A few days later I went to take a look at it and the battery was dead again. Something keeps killing the battery even without trying to run the car. But even when i first bought the battery the car still wouldn't start. Any ideas and help is appreciated very much.

I posted this in technical but I was hoping just to get as much input as possible so i posted it here as well.