Ok....
I can fill >
The solenoid on a BBD carb is there in case you have an automatic or air conditioning. This solenoid has an electrical and vacuum connection and steps up the idle when the AC comes on or drive is selected.
It is located on the front drivers side of the carb.
Below you are talking about a stepper motor, not a solenoid.
I don't know the pulse width or speed, but it will be a 12 volt spike I 'believe'. I have never taken a meter to that end of things so don't know if a DMM is fast enough to see it. Maybe try a logic probe that shows CMOS or TTL pulses? (likely just TTL being that old)
No the two pins are set into a plate. If one moves the other has to move. If only one moves, the fiber board plate inside the stepper body would be broken.
Be thankful you have 'lost' it's mate.
That used to go to the PCV shutoff solenoid which was a bad design and recalled at one point, or the TSB said to just toss it in the garbage and replace it with a plain 'T' fitting.
If you want to find out if the stepper motor is functioning, start the engine, warm it up and watch the pins in the carb while doing this. They should move. Then unplug the O2 sensor and watch to see if the pins move.
A dead O2 sensor will stop the stepper from moving. The computer just puts the stepper motor into 'limp home' mode and keeps it there.
You can also heat up the engine and disconnect the O2 sensor, then put the DMM from the sensor plug to ground to check for pulses coming out of the (unplugged) sensor.
You should see a flicker on the meter that goes from something like .2V to .8V with the engine hot. Depending on how 'good' or fast the meter is, you might just see a flicker, but a pulse is what you are looking for.
If the pins appear to be pushed all the way into the carb, and the O2 sensor has pulses, then I would next check the charcoal canister purge valve for integrity. If blown, it causes a lean situation that forces the stepper into full rich (pins all the way into the carb body) to try and compensate.
To test this, trace the PCV line to the back of the carb. There you should find a T fitting or that stupid solenoid shutoff for the PCV. Trace the other line from the T to the top of the charcoal canister down under the washer bottle. At idle, pinch this line to the canister closed. If the idle changes, the canister is dead.
Hope some of this helps.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's