Quote:
Originally Posted by jamesm
thanks for the help. i'm a bit confused though. if the crankcase vent goes back to the intake before the turbo, i agree that the air being pushed out will be metered, but the air being sucked in (which is the primary purpose of the crankcase vent, as the pcv has a check valve in it and will not allow air into the crankcase) will not be metered, and will eventually make it back into the intake manifold as unmetered charge. i noticed this from the idle/low fuel trims that we're going nuts. i've since capped the manifold to keep that unmetered air from getting back into the manifold and i have a far more stable idle (still have to log trims again, but i expect them to be improved).
so then is the idea that if i can get the crank vent tube to somewhere that is always under vacuum (in front of the turbo) it'll not pull in unmetered air? does this hold true at idle when there is very little vacuum in front of the turbo, or will a setup like this cause the same issues at idle/low-load as before?
thanks for all your help! this is driving me nuts trying to get it right lol.
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Quick comment, as soon as you hit boost, air is not sucked in. Don't worry about your fuel trims too much on idle. The unmetered air going in while on vacuum is not much to worry about.