New rebuild is running ike a swiss watch, except for one code, po1441. Not unexpected as I unplugged the entire system during the rebuild. First I found and replaced a rotted 90 going from the fuel tank to the charcoal canister. I fixed that, got a new gas cap, and cleared the cel. It came back a day later.
The rotted 90: https://i.imgur.com/VNiPsLI.jpg
The system layout:
I dont know evap systems very well, so I did some tests that I knew to do. First I tested both the tank to canister line, and canister to vent solenoid line, to see if they held vacuum. (capped one end off and used a vacuum pump) They both did, so I then checked if vacuum was getting to the bottom of the vacuum chamber/canister. Good vacuum on a vacuum gauge. So, then I checked the charcoal canister itself.
The canister: https://i.imgur.com/46FIMVk.jpg
The middle two ports are the inlet and outlet and it looks like the big one on the right is the atmosphere vent? The canister has a 4th port at the bottom. (labled “accessory” in the diagram) that goes into the vacuum chamber thats been merged with the canister) When tested, the canister only holds vacuum if the atmospheric port is capped. Is this correct? Or should I move on to testing the vent solenoid and purge solenoid? What should my next steps be?