By-passing the P.A.I.R VSV
#1
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By-passing the P.A.I.R VSV
Has anyone bypassed their P.A.I.R VSV (red one) by hooking up the reed valve directly to manifold vacuum on their 22RE? I had one of the nipples off the PAIR VSV break off, it is the side that feeds manifold vacuum to the VSV, then the other nipple routes that vacuum to the reed valve allowing air into the exhaust manifold. Toyota no longer makes the VSV, and finding one that directly matches the part number has been kind of hard.
My plan is to just run the vacuum line from the reed valve to the original port on the throttle body. I will leave the connector on the VSV to have the computer think it's opening and closing the valve, but it will just be open all the time now.
Just looking for feedback to see if this has affected drive-ability for anyone?
My plan is to just run the vacuum line from the reed valve to the original port on the throttle body. I will leave the connector on the VSV to have the computer think it's opening and closing the valve, but it will just be open all the time now.
Just looking for feedback to see if this has affected drive-ability for anyone?
#2
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Interesting. According to the manual (for a later model) the only time the VSV is closed is during deceleration with the throttle closed and the engine warm.
I'm just guessing now, but I wonder if the VSV is to avoid tailpipe backfiring. It wouldn't take much to find out.
I'm just guessing now, but I wonder if the VSV is to avoid tailpipe backfiring. It wouldn't take much to find out.
#3
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I am just going to by-pass it and see what happens. I will keep the check valve in line, as I think this keeps the vacuum going in only one direction.
I will try it tonight and update...
I will try it tonight and update...
#5
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Ok, well I just by-passed the P.A.I.R VSV and it runs the exact same as it did before. So no drive-ability issues to report.
Here is what I did...
This is how the vacuum hose and check valve were positioned before the (I think throttle cable) broke off the nipple that accepts vacuum from the intake manifold.
Another close up shot.
I then took off the vacuum line from the unbroken nipple that runs from the VSV to the reed valve below the intake.
Then I just hooked up that vacuum hose to the port on the intake where the line with the check valve went into. The reed valve of the P.A.I.R system is now effectively receiving manifold vacuum all the time now.
After looking through the FSM and putting everything together, the VSV receives a signal from the ECU when decelerating and at WARM idle only, to cut vacuum to the reed valve. Otherwise the reed valve is "open" or receiving vacuum at all other points. When the valve is open, it is injecting air into the exhaust to promote proper burn off in the catalytic converter. When the valve is closed, no air is being fed into the catalytic converter, due to I think, not overheating the converter. So I guess the downside to this is you may have higher catalytic converter temps. I have an inferred thermometer that I will take temps of to see just how hot it gets at warm idle.
Here is what I did...
This is how the vacuum hose and check valve were positioned before the (I think throttle cable) broke off the nipple that accepts vacuum from the intake manifold.
Another close up shot.
I then took off the vacuum line from the unbroken nipple that runs from the VSV to the reed valve below the intake.
Then I just hooked up that vacuum hose to the port on the intake where the line with the check valve went into. The reed valve of the P.A.I.R system is now effectively receiving manifold vacuum all the time now.
After looking through the FSM and putting everything together, the VSV receives a signal from the ECU when decelerating and at WARM idle only, to cut vacuum to the reed valve. Otherwise the reed valve is "open" or receiving vacuum at all other points. When the valve is open, it is injecting air into the exhaust to promote proper burn off in the catalytic converter. When the valve is closed, no air is being fed into the catalytic converter, due to I think, not overheating the converter. So I guess the downside to this is you may have higher catalytic converter temps. I have an inferred thermometer that I will take temps of to see just how hot it gets at warm idle.
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