gen v pcv fix....WTF....

BoostJunki3

Slow M90 Setup
Oct 13, 2009
370
0
Plainfield, IL
ok this is the issue im having....the pcv nipple on the back of the genv is creating a suction.....the nipple on the l67 tb is also creating a suction....

ive seen write ups that say connect the one on the genv to the tb to fix it and block off the evap connection on the blower, mine is jb'd shut.

i had no idea pcv wasnt functional until i heard a loud whistling when driving and when i tried to pop off the oil cap it had a suction (at this time both nipples were vac capped.) when i remove the genv cap and leave the tb capped i get no oilcap suction or loud whistling/squealing. here are pics below about what im talking about.....could the pcv just be bad? weird thing is i drove with both capped for awhile with no squealing or whistling but i just fixed a leaky front valve cover today and the gasket was bad so maybe it was escaping there and preventing whistle....pcv has free play when shook and the plastic shaftgoes in then pcv valve then spring and cap.....cant figure it out.

l67 tb connection
mms_picture-1.jpg


genv connection on back
mms_picture_1.jpg
 

M@

Somebody buy this thing
Nov 26, 2007
2,871
2
my gen v nipple on the genv has vacuum when left un plugged is this normal? my maf is connected to my filter (lq4) so now what do i do?

Normal, yes.

Do what James said, connect the port on the Gen5 somewhere between the throttle blade and the MAF. Has to be after the MAF so the air has been metered, but before the throttle blade so as to not just create a vacuum.

If someone told you that the port on the stock TB should be connected to the PCV, they misinformed you. The port in the Gen5 is the PCV inlet, which needs to draw air at ambient pressure, i.e. before the throttle body blade. This inlet feeds metered air through the crankcase to ventilate vapors therein, and then is sucked back into the engine through the PCV valve and into a port just before the supercharger rotors.

You can just leave that port to suck ambient air, with a mini-filter over it, but any air drawn through there will not be registered by the MAF, and can throw the fuel trims off, sometimes considerably so, not good for your tune. For this reason, you need to create a place, somewhere AFTER the MAF but BEFORE the throttle blade, for air to be drawn out of the intake tract and into that port on the Gen5.

Hopefully that makes sense...
 
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