Ok i just saved 300zx from a friend of mine who has blown two cars engines prior to this car.I just rebuilt the transmission put it in and tried to start it but it wont start. It turns over but it wont start. Its a manual trany so i tried to start it by pulling it in first and it started but it wont stay on. what are some things i should do before i jump the gun and start working on compression problems? any help would be greatly appreciated.