blackcloud50 said:I see alot of confusion with regards to this particular subject in countless posts and now I am confused somewhat. Here I cut and paste a response that I recieved from one member:
Removing the TB/VC line is not a good idea as this is the source of fresh air for the crankcase. It is the fresh air running through the crankcase that picks up all of the volatile contaminants from the crankcase, to be purged via the pcv.
No TB/VC hose = No Fresh Air = Lots of Contaminants in oil.
The only time this line should be eliminated is if the engine is running boost, or there is a vac pump running on the crankcase.
Using a breather on a pcv system will essentially create a vac leak, as the air entering the crankcase via the breather will not be metered by the MAF. This can cause typical vac leak symptoms.
You may be right about the confusion. In reference to the quote you posted... I don't see what the problem would be having unmetered air enter into the crank case. That portion of the motor is not used for combustion. If that were the case, then you'd not be able to run the motor without the oil filler cap on (which obviously, you can), not to mention the probably THOUSANDS of folks out there that run valve cover breathers on both carb and fuelie applications.
The oil filler neck to throttle body hose is separate from the PCV system. What they have in common is that BOTH vent positive crank case pressures. The PCV from an area that's inhearantly rich in unspent that can also have a tendancy to PULL air during a portion of one engine rotation and PUSH air during another portion of one engine rotation. Thus the requirement for the PCV check valve. The valve cover area (so far as I know) is not effected to the same degree. It's almost a constant PUSH of air form that location, not a PULL or vacuum.