PCV question-injuneer??
10-15-2003, 09:38 PM
#1
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PCV question-injuneer??or anyone??
I know there is a thread on this right now but I have a question and I did not want ot steal anyones thread. There is long black hose that comes off of the passenger TB and goes to the valve cover and is attached with an elbow fitting. I understand that this is part of the PCV system. I took mine off at the valve cover and there is no air suction or pressure of any kind. Should there be? I have suction at the PCV valve itself.
Last edited by ead94z28; 10-15-2003 at 09:48 PM.
10-15-2003, 10:06 PM
#6
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do you have an airfoil? they block the passage in the TB, you could take the TB and make sure its clean around all the passages
be sure to clean the top out
if you dont have emissions you can just put a breather filter on the valve cover hole, and plug the TB hole and it will work just fine injuneer has a good write up in a thread on this. click here http://web.camaross.com/forums/showt...&highlight=pcv
jesse
be sure to clean the top out
if you dont have emissions you can just put a breather filter on the valve cover hole, and plug the TB hole and it will work just fine
injuneer has a good write up in a thread on this. click here http://web.camaross.com/forums/showt...&highlight=pcvjesse
10-16-2003, 11:04 AM
#10
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There will not be any vacuum at the throttle body end. That line supplies clean, MAF measured air from a port in front of the throttle blades (not exposed to intake manifold vacuum, except at WOT).
The air flows from the connection on the side of the TB, down the black rubber hose, into the passenger side valve cover, and is pulled through the crankcase and lifter valley, through the PCV valve, and dumped into the intake manifold (drivers side of the manifold on 93/94, a port under the TB on the front of the manifold on 95-97). If you see any vacuum at all, at idle, it should be at the valve cover, not at the TB. But remember, there are springs in the PCV valve to limit flow under certain conditions, so you might not see much in the way of vacuum at all at idle.
Removing the system, and adding a crankcase breather, is equivalent to intentionally adding a vacuum leak to your intake (94-97), allowing air that has not been measured by the MAF to enter the combustion process. The long term fuel corrections can deal with this "leak" fairly easily.
The air flows from the connection on the side of the TB, down the black rubber hose, into the passenger side valve cover, and is pulled through the crankcase and lifter valley, through the PCV valve, and dumped into the intake manifold (drivers side of the manifold on 93/94, a port under the TB on the front of the manifold on 95-97). If you see any vacuum at all, at idle, it should be at the valve cover, not at the TB. But remember, there are springs in the PCV valve to limit flow under certain conditions, so you might not see much in the way of vacuum at all at idle.
Removing the system, and adding a crankcase breather, is equivalent to intentionally adding a vacuum leak to your intake (94-97), allowing air that has not been measured by the MAF to enter the combustion process. The long term fuel corrections can deal with this "leak" fairly easily.
10-16-2003, 12:13 PM
#12
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I also wouldn't worry about the PCV system with regards to "emissions testing". In the "old days" (when I was probably your age 
) they used to vent the crankcase by using a "draft tube"... simply a short length of pipe the exited straight down at the bottom of the engine. Air flowing under the car sucked the vapors out of the crankcase. The "closed" PCV system is an attempt to contain those vapors by recycling them to the intake manifold. Not having the system working correctly would simply allow those vapors to escape from the engine in some other way, not affecting the tailpipe emissions.
) they used to vent the crankcase by using a "draft tube"... simply a short length of pipe the exited straight down at the bottom of the engine. Air flowing under the car sucked the vapors out of the crankcase. The "closed" PCV system is an attempt to contain those vapors by recycling them to the intake manifold. Not having the system working correctly would simply allow those vapors to escape from the engine in some other way, not affecting the tailpipe emissions.
10-16-2003, 12:20 PM
#13
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Originally posted by Injuneer
There will not be any vacuum at the throttle body end. That line supplies clean, MAF measured air from a port in front of the throttle blades (not exposed to intake manifold vacuum, except at WOT).
The air flows from the connection on the side of the TB, down the black rubber hose, into the passenger side valve cover, and is pulled through the crankcase and lifter valley, through the PCV valve, and dumped into the intake manifold (drivers side of the manifold on 93/94, a port under the TB on the front of the manifold on 95-97). If you see any vacuum at all, at idle, it should be at the valve cover, not at the TB. But remember, there are springs in the PCV valve to limit flow under certain conditions, so you might not see much in the way of vacuum at all at idle.
Removing the system, and adding a crankcase breather, is equivalent to intentionally adding a vacuum leak to your intake (94-97), allowing air that has not been measured by the MAF to enter the combustion process. The long term fuel corrections can deal with this "leak" fairly easily.
There will not be any vacuum at the throttle body end. That line supplies clean, MAF measured air from a port in front of the throttle blades (not exposed to intake manifold vacuum, except at WOT).
The air flows from the connection on the side of the TB, down the black rubber hose, into the passenger side valve cover, and is pulled through the crankcase and lifter valley, through the PCV valve, and dumped into the intake manifold (drivers side of the manifold on 93/94, a port under the TB on the front of the manifold on 95-97). If you see any vacuum at all, at idle, it should be at the valve cover, not at the TB. But remember, there are springs in the PCV valve to limit flow under certain conditions, so you might not see much in the way of vacuum at all at idle.
Removing the system, and adding a crankcase breather, is equivalent to intentionally adding a vacuum leak to your intake (94-97), allowing air that has not been measured by the MAF to enter the combustion process. The long term fuel corrections can deal with this "leak" fairly easily.
So, the passenger-side breather tube is really a two-way street. Metered air drawn INTO the crankcase via the breather hose during high vaccum conditions, blowby exiting OUT of the crankcase via the breather hose and into the intake during low vaccum conditions.
People that remove the breather hose and put one of those K&N breather filters on top of the passenger valve covers are not improving anything. They run the risk of vapor build-up in the crankcase, which contaminates oil, and runs the risk of a crankcase explosion. Also, they are gross polluters. PCV was probably the first effective emmisions system appled to the auto, and there are really no negatives associated with it.
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