Volt gauge started acting funny won't stay running.

[NitrousJunkie]

I just got done doing an opti, waterpump msd coil and wires, car ran great for over a week...

Last week while I was driving it started to almost die while cruising, that's when I look down and see 0 volts, so I take it home, go out to start it and my volts are good, next day 0 then it popped up into normal now I have 0 and car will fire right up and die right away, also it wouldn't crank when I had jumpers hooked up for 10 mins but did and ran great 20 minutes later and ran good for about a minute then my idle kept dropping up and down then it died, now if you try to start it, it will fire up and die right away.

The kicker? Both the alt and battery tested good, connections are tight and not corroided.

Any idea's?

Thanks alot, I'm stumped - volt regulater? Idk need help.