86-300sdl,

I have observed that the monovalve has a very long 1/2 inch stroke length when I tested it with the battery and monovalve coil outside the housing. I believe that the monovalve with the spacer o-ring still closes as normal since I do not see the temperature of the center vent rising when the climate control is set to cool without air conditioning.

I tested the heat at 65 mph and saw 145 degree heat. I think the pump does help at lower speeds. I noticed that the heat increases when the engine rpms rise. This condition has not happened in the last week and temperature has been comfortable.

I would like to do more observations of the solution such as long high speed drives, but this is much better than having no heat at all.