well, I don't think it's my alternator anymore.
Here's what I did to check it...I did the voltmeter thing, it checked out find. I turned the car on by jumping it, and this is that happened afterwards.

I had the car on for about 30 minutes. I figured, that, if it was the alternator, the battery wouldn't get charged so it would die. Correct?

Anyways, assuming that that is correct, I let the car idle. I noticed that The car idled at about a solid 1,000 rpms, but every now and then it would jump strangely between 1,000 - 1,300 "violently". Whenever I revved the engine to about 2,500 or so, it would jump to 2,500 violently, go down some, and then jump back up (I wouldn't make it do that, I'd keep it at 2,500, it would just jump). So, would this be a fuel problem? an air problem? Something in my Fuel Injection/Air Box?

Why would it idle and jump RPMs so strangely.