Purge cannister solenoid

Based on vacuum input, this valve controls the flow of fuel vapors from the Charcoal Canister to the intake. It is controlled by the Thermactor Air Diverter Solenoid, but I'm not sure whether vacuum opens or closes it. Since it is often called a "Shut-Off" valve, I assume vacuum would close it. This item is missing from Chapter 3 of Ford's Emission Diagnosis manual for 1984.

You can turn it off with the TwEEcer useing the scalar tag Canister purge min RPM


Or you can put a 10K resistor in its place and fool the EEC into thinking its still there. cut the connector off, used a piece of heatshrink and soldered the resistor across the wires then taped it back into the harness. No more codes.
There is no feedback for the EEC to check to see if the solenoid is actually obeying the command. It is simply sensing the output voltage to the solenoid's coil which is a function of the coil's resistance. Other solenoids affect engine function like EGR and the EEC can see if the EGR is working because it affects HEGO output. One caution, for those attempting this on a vehicle that is NOT a racecar. It is likely that the effect any device has on the addition or subtraction of air or fuel, in the intake tract, after the MAF, has been accounted for in the EEC Program. Therefore, if you cannot inform the EEC of these changes, you may encounter driveablity or emissions problems you had not anticipated.