Horrible idle and engine screaming noise

[Dragginz]

I've avoided posting any questions on here for as long as possible (creeping, searching searching searching for previous answers, etc), but I haven't seen anybody else answer this one.

I bought a 1993 240sx from a guy down in Orange County RIFE with issues (no power steering, helicopter noises while driving, dents, etc), but...who cares? It's a 240 Long story short, I need it to pass smog (fml), and it fails horribly. Previous reading has advised me to remove, clean, and check my EGR (along with EGR engine codes), so instead of spending hours going nuts with the bolts hidden under the intake manifold, I pulled the whole thing (fuel rail and all that jazz), cleaned up the EGR, finished putting it all back together last night - however, the previous owner(s) did some wonky stuff to the KA24DE in there, and I did my best to clean up what I could. Upon starting the car, the engine jumped right up to about 2.5K RPMs, stayed there for about 3-4 seconds, and then dropped down to < 1K and started idling horribly, and then died. If you keep a little gas on it, it'll continue to run, but just idling, dies. I had my buddy keep it running for a minute, and I can clearly hear air sucking towards the rear of the engine, right around the fuel rail. After killing the engine and looking for a vacuum leak (finding nothing), we fired it back up to see if we could pinpoint the noise - THIS time, however, the engine started to scream and we promptly killed it again. It doesn't sound anything like a belt, it's much more high pitched, almost like metal on metal. Checked the oil, there's plenty, and I'm pretty much at a loss as to what's going on here..... any thoughts?

(And while I'm asking, the previous owner also has the line that goes from each of the intake manifold runners to that big tree/T rail thing capped off with a bolt...any idea where that's SUPPOSED to go? The other weirdness is...there's no vacuum line to the intake-manifold butterfly valve PCV thing on the end of the manifold, so they're just stuck open all the time...does that matter? And where SHOULD that plug into?)

Thanks in advance, I know it's a lot to read....

[ZeroPunk]

Not too sure on what the screaming noise you're referring to would be but under the intake manifold on my car there was 4 lines that go down and hook into the pcv valve. If that's disconnected that is part of why you failed emissions.

[waxdnuggz]

Its 100% a vacuum leak. Check the vacuum lines from each runner and the on that goes to the iacv I've had this happen on a few 240s. The lines connected to the runners get so dry and brittle that they crack as soon as you unbolt your intake.

Here's a trick I found out. If you smoke (anything) then inhale and blow it into any vacuum line if you see smoke blow from anywhere you have a vacuum leak. Take a brake parts cleaner can or spray paint or something and take off your intake pipe and plug the tb with the can and a coupler so it doesnt cone out the tb and trick you.

[Dragginz]

Shoot, sorry for not replying sooner! You guys had it right, thanks a ton for your help