Throttle body without vent tube?
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Throttle body without vent tube? My 2000 TA is set up with a vented TB from the factory. I had someone add a Mighty Mouse catch can. I currently have a vent line running from the driver's side rear valve cover to the TB. Can that line be plugged or can it be run to the passenger rear side valve cover if I use a TB without the vent pipe?
Last edited by wannafbody; Apr 30, 2023 at 01:15 PM.
Thread Starter
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From: Pittsburgh
I guess the consensus is that the Mighty Mouse can acts as the pcv and the other lines can be capped or the valve covers connected, it doesn't seem to matter. If that is incorrect, let me know.
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A catch can is just ... a catch can. It can't possibly "act as" the PCV. It plumbs into the otherwise unchanged suction PCV line.
The rest of the system needs to stay exactly as it came. Especially in a car with a MAF. Dirty crankcase air that the PCV sucks into the intake passes through the catch can, and liquid oil and whatnot is allowed to precipitate out of it, just like water does in the dryer in a compressed air system.
Not sure about "vent". Never seen or heard of any such in one of these systems.
There's a line off the TB or intake (varies from one system to another) that's BEHIND the throttle blades such that it's exposed to intake vacuum and has the PCV valve at the other end (which is the line that the catch can should be installed in), and another off the TB that originates BEFORE the throttles (atmospheric pressure, i.e. not vacuum) but BEHIND the MAF that brings clean filtered "makeup" air into the crankcase to replace what gets drawn out through the PCV. AFAIK the 1st one is on the driver's side VC (unless you have the LS6 valley cover and associated setup) and the other on the pass side. Any other arrangement won't work since you have a MAF. So I'm guessing that whatever your question is, the answer is "no".
The rest of the system needs to stay exactly as it came. Especially in a car with a MAF. Dirty crankcase air that the PCV sucks into the intake passes through the catch can, and liquid oil and whatnot is allowed to precipitate out of it, just like water does in the dryer in a compressed air system.
Not sure about "vent". Never seen or heard of any such in one of these systems.
There's a line off the TB or intake (varies from one system to another) that's BEHIND the throttle blades such that it's exposed to intake vacuum and has the PCV valve at the other end (which is the line that the catch can should be installed in), and another off the TB that originates BEFORE the throttles (atmospheric pressure, i.e. not vacuum) but BEHIND the MAF that brings clean filtered "makeup" air into the crankcase to replace what gets drawn out through the PCV. AFAIK the 1st one is on the driver's side VC (unless you have the LS6 valley cover and associated setup) and the other on the pass side. Any other arrangement won't work since you have a MAF. So I'm guessing that whatever your question is, the answer is "no".
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From: Pittsburgh
The explanation I read was that by locating the can to take vapors from the front of the intake and vent them to the passenger valve cover it reverses the air flow through the PCV system(I'm using a DLS2 intake). That would allow the drivers side rear valve cover nipple to act as a clean air vent.
Last edited by wannafbody; May 1, 2023 at 07:54 AM.
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That's not the way "vapors" go. The can doesn't "take vapors from the front of the intake and vent them" in any manner way shape form or fashion. That's just not true.
As built, the PCV (driver's side VC, or valley cover sometimes) draws vapors OUT of the crankcase and INTO the intake to be burned, by way of vacuum; and fresh clean filtered "makeup" air at atmospheric pressure, that's been through the MAF and thus been metered so that the ECM knows it's there and will supply fuel for it accordingly, is supplied into the pass side VC.
The catch can belongs in the PCV line (the one with vacuum on it) where it can trap liquids that would otherwise be drawn into the intake. It doesn't alter anything about how the PCV system works. It causes no change in the fundamental operation of the system, any more than putting a dryer in line with your paint gun or other air tools, makes your air compressor work any differently.
Brand of intake doesn't matter. The PCV system still works the same way.
Only exception to this is, if you're using forced induction; since then, the intake sometimes has pressure in it instead of vacuum, which obviously would "reverse" everything. Obviously a PCV system based on vacuum can't possibly work right in that situation. You don't mention any of that so I'm guessing that doesn't apply.
Not sure about "explanation" or "read" or "reverses" or any of that. My guess is that you misunderstood something. I'm glad I was able to help set you straight.
As built, the PCV (driver's side VC, or valley cover sometimes) draws vapors OUT of the crankcase and INTO the intake to be burned, by way of vacuum; and fresh clean filtered "makeup" air at atmospheric pressure, that's been through the MAF and thus been metered so that the ECM knows it's there and will supply fuel for it accordingly, is supplied into the pass side VC.
The catch can belongs in the PCV line (the one with vacuum on it) where it can trap liquids that would otherwise be drawn into the intake. It doesn't alter anything about how the PCV system works. It causes no change in the fundamental operation of the system, any more than putting a dryer in line with your paint gun or other air tools, makes your air compressor work any differently.
Brand of intake doesn't matter. The PCV system still works the same way.
Only exception to this is, if you're using forced induction; since then, the intake sometimes has pressure in it instead of vacuum, which obviously would "reverse" everything. Obviously a PCV system based on vacuum can't possibly work right in that situation. You don't mention any of that so I'm guessing that doesn't apply.
Not sure about "explanation" or "read" or "reverses" or any of that. My guess is that you misunderstood something. I'm glad I was able to help set you straight.
