I have a 1988 Jeep Comanche, w/4.0 automatic,w/only 71,000 original miles on it. It overheated last week, and I have changed the thermostat and now the water pump-and it still is overheating .Oh and I am trying to run a coolent system flush thru it but it is still overheating . the heater is working fine. what the heck else can be the problem?????

Check your coolant temperature switch, and also after you replaced the waterpump, and thermostat, did you get all of the air out of the system, on a lot of the jeeps , on the thermostat housing , there is a threaded screw in the housing, i believe it takes a allen wrench to remove the screw, this will let air out of the cooling system, the best way to do this , is when you are refilling the system, remove the screw, and when the coolant reaches the area of the screw and starts to come out, replace the screw, and this bleeds the system.