smog test issues

Im hoping someone can help me locate the where the "TO TANK" vacuum hose from the charcoal vapor canister goes.  Im in California, home of the Smog Nazis and am trying to get a 79 Concord 258's smog equipment sorted out.  The car has a smog legal fuel injection retrofit except they used an electrical temp sensor in place of the ancient and unreliable 5 port thermal vacuum switch/coolant temp over-ride switch and heaven forbid we use something that works!  Ive installed a new switch but the line from the charcoal canister that is labeled simply "to gas tank"  is not connected to anything and Im unable to find what it should go to!  I cant find a diagram or explanation so PLEASE, Anyone know? Smog tests cost close to $100, so I dont want to fail again.  Thanks in Advance

Hi Joe.  There is a metal line inside the hood connected to the "fuel return" on the back of the throttle body by a rubber hose. Im thinking maybe that is the line referred to as "From Fuel Tank" in the sticker, tho even the written installation instructions dont cover this. The vapor canister is located inside the wheel well behind the headlights (had trouble finding it!) with the hoses passing thru a hole into the engine bay.   Are there 2 lines from/to the  gas tank or am I overthinking this trying to connect lines to nowhere?

Edited by tfhofstad - Oct/30/2017 at 12:14pm

Thanks for your help Pacerman.  I bought a CD of the shop manual - no help this time but good to have.  Put the car up and crawled along under it. I found the 2 inch remains of the line at the top of the tank, cut off and a bolt stuck into it to plug it!  Another "why did they do that?" moment.

the line that runs down the drivers side of the car should have first gone to the tip-over valve (as in, tip the CAR over) i think up inside the rear quarter panel, not in the trunk (dont want gasoline in there) but up near the fender well. from there down to the tank. the tipover valve is obscure, i think it is meant to plug the charcoal vcanister vent line in case the car rolls over. with the sealed gas cap, in an upside down car that tinyl little line wouldnt leak fuel per se, but would be the *air vent* that would allow gasoline to exit elsewhere. like the little air vent cap in red gas cans, they dont flow til you open the vent.