87 Town Car Heat Issue

I just acquired an 87 town car that has been sitting for six years. I got everything running fine except the heat. I replaced the heater control valve, the thermostat, and flushed the system. The line going in and out of the heater core are both hot but I am still not getting any heat. I get a few seconds of heat when I go up a hill and get on the engine hard. Also the auto climate control shuts off when I change the temp. to hot. The final issue is that the location where the is blowing sometimes automatically changes to the defroster. Does anybody have any ideas.