What does this 968 Fuel Tank Vent Valve do?
08-04-2014, 07:59 PM
#1
Rennlist Member
Thread Starter
What does this 968 Fuel Tank Vent Valve do?
I've been troubleshooting a fuel vapor smell in the cabin, and I think I resolved it with putting some new hose clamps on and tightening others in the carbon canister system.
However, when I was testing everything, I found that I could get the vacuum valve (item 15 below) to change state when applying/removing a vacuum from it, but I could not get the electric solenoid valve (item 14 below) to change state when it had 12 VDC applied/removed.
This was based on my "blow/suck" oral test.....it has 46 ohms, you can hear it pick up when you energize it (when the ignition goes on, it is powered from the ECM), but it really has no effect on being able to blow or suck through it, it still seems open.
So I bought a used one on ebay. New ones are over $200. It also has 46 ohms, I can hear it pick up when energized, but once again, it really has no effect on being to blow/suck through it.
What would be the purpose of this valve? I have no idea and have no idea if mine is working correctly or not, would think it would change states.
There is an arrow on it (see adjacent to electrical connector) which I would guess means it would allow vapor to go from the canister side back into the intake manifold, but not allow vapor to go from the manifold to the carbon canister.
It plugs into the intake manifold on left hand side in the picture above, and goes off to the carbon canister on the vacuum side. The vacuum is connected right at the throttle plate, so only when you are off throttle and vacuum is present behind the throttle plate does the vacuum valve open.
Here is my thread on the fuel smell with more pictures including the carbon canister, it no longer is pumping the vapor into the car through the air vents.
https://rennlist.com/forums/968-foru...n-driving.html
Thanks for any input!
However, when I was testing everything, I found that I could get the vacuum valve (item 15 below) to change state when applying/removing a vacuum from it, but I could not get the electric solenoid valve (item 14 below) to change state when it had 12 VDC applied/removed.
This was based on my "blow/suck" oral test.....it has 46 ohms, you can hear it pick up when you energize it (when the ignition goes on, it is powered from the ECM), but it really has no effect on being able to blow or suck through it, it still seems open.
So I bought a used one on ebay. New ones are over $200. It also has 46 ohms, I can hear it pick up when energized, but once again, it really has no effect on being to blow/suck through it.
What would be the purpose of this valve? I have no idea and have no idea if mine is working correctly or not, would think it would change states.
There is an arrow on it (see adjacent to electrical connector) which I would guess means it would allow vapor to go from the canister side back into the intake manifold, but not allow vapor to go from the manifold to the carbon canister.
It plugs into the intake manifold on left hand side in the picture above, and goes off to the carbon canister on the vacuum side. The vacuum is connected right at the throttle plate, so only when you are off throttle and vacuum is present behind the throttle plate does the vacuum valve open.
Here is my thread on the fuel smell with more pictures including the carbon canister, it no longer is pumping the vapor into the car through the air vents.
https://rennlist.com/forums/968-foru...n-driving.html
Thanks for any input!
