engine question

[beefcakext]

i just bot a 91 240sx and the person i bot it from says it runs good for maybe a half a hour then dies and the battery is dead. I think this because of a bad alternator. So i tried un hooking the battery while it was running and there was a noticable difference. it would idle steady then die down then go back up to normal. when the battery was charged up it ran clean with no noises but then would act the same way wanting to die. Like i said im almost posittive its the alternator but if you have any other ideas that would be great.

[Silvia007]

Alternator 100%... or if you're lucky, poor alternator wiring. I'd redo the wiring if I was you.

[RMiller]

Alternator for sure. While it's running well drive it to your local parts store like autozone or kragen and have them test the alternator. If it fails, get it rebuilt or get a new one.

[carofchoice]

if its the alt, i got one from a 91 for you. 35 shipped