Spittybug
12-17-2011, 03:46 PM
I was doing a little engine bay cleanup today when I started eyeballing my oil filler vacuum hose configuration and started having some questions.
In the stock setup, one side of that cap is plumbed to the air cleaner (fresh air in), passes through the cap, drawing crankcase vapors and exits via short hose to the base of the cold start valve. This is in turn hard piped down to the base of the manifold where it is distributed to all the cylinders. This is therefore another route for air to bypass the butterflies of the throttle body, like an idle circuit. Do I have that correct?
So my question is, does the filler cap have some form of regulator in it to restrict the amount of air that can be pulled through it? I couldn't find this in the manual anywhere, but it must be there. For my EFI setup I have this plumbed to the throttle body vacuum, not the manifold. I am therefore upstream of the butterflies and the air that gets past them is a function of my idle control valve or the small permanent air channel which I think serves a decel function. I don't think I have any problem with this setup and I'm not blowing oil out of my dipstick hole or anything like that. More or less just wondering about the stock setup and the the amount of air going in from non-idle valve, non throttle body sources.......
In the stock setup, one side of that cap is plumbed to the air cleaner (fresh air in), passes through the cap, drawing crankcase vapors and exits via short hose to the base of the cold start valve. This is in turn hard piped down to the base of the manifold where it is distributed to all the cylinders. This is therefore another route for air to bypass the butterflies of the throttle body, like an idle circuit. Do I have that correct?
So my question is, does the filler cap have some form of regulator in it to restrict the amount of air that can be pulled through it? I couldn't find this in the manual anywhere, but it must be there. For my EFI setup I have this plumbed to the throttle body vacuum, not the manifold. I am therefore upstream of the butterflies and the air that gets past them is a function of my idle control valve or the small permanent air channel which I think serves a decel function. I don't think I have any problem with this setup and I'm not blowing oil out of my dipstick hole or anything like that. More or less just wondering about the stock setup and the the amount of air going in from non-idle valve, non throttle body sources.......