I've got hopefully i pretty easy question. After i got done with my swap, i basically just left the pcv system unhooked. I dont have the stock intake obviously, so theres no provisions for clean air intake off of it other than the IACV and the throttle body. In an effort to nail down my bouncy idle issue, I decided to put the pcv system back together today and i have some concerns. Heres how i hooked it up:

 

Both head breathers are T'd together, then the leg of that T goes to the Y shaped fitting ontop of the crank case breather, then from there i have the big 5/8ths" hose going to the PCV valve on the intake plenum.

 

I then started it, and right away the engine sounded LOUD. Very very loud lifter noise. I revved it out a couple times and the noise went away. I turned it off, and cracked the oil filler and a huge rush of air went in. For some reason i dont think this is the way it's supposed to be hooked up.

 

So, basically, how is the head breather/crankcase/pcv system supposed to be setup? I've got nothing to go off of and for some reason i cant find any hose routing information online, just vacuum line diagrams for 80s loyales

Might have found a solution. I changed my search wording (breather instead of pcv) and came up with this gem (hearsay from a service manual):

 

"In a part-throttle condition, the blow-by gas in the crankcase flows into the intake manifold through the connecting hose of crankcase and PCV valve by the strong vacuum created in the intake manifold. Under this condition, fresh air is introduced into the crankcase through the connecting hose of the rocker cover."

 

Sooooo, intake vacuum comes through the pcv, to the big hose going to the crank breather hose fitting, and fresh air is supposed to get sucked into the rocker covers, down through the oil galleys, and into the crankcase, then up through the breather hose into the intake?

 

My question then, is what is that extra leg on the crank case fitting dealy. Theres a 5/8ths nipple, and branching out of the base of that is a 1/2" nipple. What's that for, then?

The large fitting on the bottom goes to the Oil seperator on the back of the block and then oil drains down to the pan. The top fitting goes to the PVC valve on the intake. The 1/2" fitting coming off the middle goes to the Intake air box on the back of the intake manifold.

 

Depending on the year and model, it goes to different locations. Look over the airbox and you will see the fitting.

Oil separator eh? Hmm, can't find one in any of my engine parts location pictures.

 

What i've done is run the large 5/8ths hose directly to the pcv valve, run the small 1/2" nipple from that fitting to a T fitting that connects to both the head vents, T'd into that line again, and ran that hose out to the IACV intake hose to another T. I hope that makes sense, but it's hooked up the way the manual describes how the system works.

 

High vacuum pulls crank fumes from the large fitting on the block, as well as a bit of fresh air from the smaller fitting piggied to the large block fitting. The smaller fresh air hose is connected with the head vents as well as vented to the intake hose before the throttle plate but after the MAF. At low engine vacuum, the case fumes are drawn out through both the PCV valve and the fresh air connection out to the intake hose.

 

Jeeze, hard to explain, but its working the way it should now