i rebuilt practicly everything except the block of my engine, and yesterday after reassymbly i started the car and all was well. after about 45mins of it ideling perfectly in my garage i decided to go for a test drive, i drove around slowly and finnaly decided to actually go above 2k... as soon as i hit about 3k the RPM's jumped to like 6k then to 2k then up to 8k, then started rev limiting at just under 3k. now the whole time the needle was bouncing around i know the actual engine speed never exceded 4k, probably closer to 3.5.

i was fearful when the tach jumped so i pulled into a parking lot to turn around, as i slowed i noticed the RPM's dropping off rather quickly, then the dash board started to make a rapid "click" (electric on -off sound) and all the lights dimmed. i tried to give gas to keep from stalling and it died off instanty, and for 30mins it wouldn't start so we called a tow.

Today i went out and tried to start the car and it gave me a hard time, so i tried once more while rapidly pushing the gas and it started. it now starts no problem, and idles no problem. the only thing is if i hit >3k the engine falls off to 0rpm's and no matter what it just stalls and the CEL dimmly lights but never throws a code. also if is step on the gas hard and let off before 3k (by sound of engine) the tach will wildly bounce to 8k then back to 0k and everywhere else even though as soon as i get near 3k i let off.
can anyone point me in the right direction
Things ive ruled out:
-bad battery
-bad altenator
-(checking TPS tonight)