So we are fixing vaccum leaks on my buddies 89 305 LB9 T/A and we noticed that on the charcoal canister the plug labeled as air has no hose on it and just open. On a 92 we saw at a yard it had a line plugged in there going to the fender. Where does this hose go to or is it just a vent?

Also when its opened, the car starts but struggles and stalls, with it plugged up, it will start but idle higher but continues to run.

Also if anyone can link or show a decent vaccum diagram to pin point any leaks, it will be great, so far I have found most of what I know from my TBI lines but the charcoal canister is different as I stated.


Any help would be appreciated.

 

I think it is just a breather.

Taken from:
https://www.thirdgen.org/forums/tpi/486643-what.html

On my car there is a diagram on the radiator support that shows the charcoal canister and vacume lines. I just checked www.compnine.com I found a diagram that shows the charcoal canister on the 89' LB9 Here is a direct link http://www.compnine.com/index.php?u=...03&grouptype=B

 

That is the canister purge port, it is a full vacuum leak if it is not plugged. Plug it and the car should run right. If you run a canister, then the ECM controls canister purge from the solenoid on top of the canister. I believe that the Tank line and the Purge Line are the only two that you have. Tank line goes to the tank vent line (obviously) then the purge line runs from the port on the solenoid over to the throttle body 3/8 hose connection.