For the past week my car has been acting WACKY. I am able to monitor the voltage from my turbo timer and at idle I and at 12.0-12.3 volts. As my rpms increase i lose voltage. While driving I am only making 11.0-11.3 volts. I replaced my S14 SR20DET alternator with one from a S13 SR20DET, and now I am making less power than the S14 alternator. This problem has gotten so bad that i have to jump start my car every time i want to drive it. Also i have noticed that if the car sits for a while that the battery slowly goes dead. The battery is only a few months.

all help i greatly appreciated........