Originally Posted by Arthur Dalton

If running WD40 thru the valve and lines does not clean it up , I have a good technique for stubborn ones with stuck pintles

The main part that hangs up is the pintle pin from the solinoid ...so, you take the valve off the car and squirt BP Blaster or carb cleaner into the valve and leave it over-night UPSIDE DOWN... that gets into the pintle pin and frees it up. The trick is the next day, you hook 12V battery power to one terminal and touch the other very rapidly ON/OFF..that exercises the pintle pin and frees it up.. some tapping on the side helps.....you will know when it is free b/c you wll hear/feel it clicking.
You then blow air thru the vavle ports in the direction of the arrow.

When you can feel it pulse and you can blow thru it only in the direction of the arrow, you are done and it can be installed on the car w/arrow facing engine flow.
Then idle until up to temp and feel it in your hand , ..you should feel the pulses [ 5-20Htz].
You may also want to take an Om reading across the sol. terminals before cleaning to be sure the coil is good.,, you are looking for 40-50 Ohms.....if no , don't bother..