Just something I had in my Q-jet folder - not sure if is good info or not (but it sounds about right):
MC solenoid you can bench test very easily with no special tools. I do 2 tests on them:
1. At room temperature (not hot, not cold) unplug it and check for resistance between the 2 poles of the MC solenoid. Spec is about 20 Ohms. If it's significantly higher or lower, it's shot, regardless of whether it apparently works or not.
2. The solenoid is just an electro-magnet that operates on a full 12V of battery voltage (cycled by the ECM when the engine is running). You can run some temporary jumper wires over to it from the battery to do a simple field test. Every time you complete the circuit (polarity does not matter) you should hear a click (pulling the rods down). Every time you break the circuit again you should hear another click (the rods jumping back up). You should be able to click it up and down as fast as your little fingers can make and break the connection- it moves those rods REAL fast.
