I have a carb'd '88 Accord LX. The car will run fine while it is cold outside but as soon as it gets hot outside and it has been running awhile and if you let it idle for awhile or if Im going short distances from red light to red light it will begin to overheat. But after you start to drive and dont slow down it will cool down. I have plenty of coolant in the radiator. What is causing it to overheat?

 

First thing that comes to mind is the thermostat, make sure it has the correct one and it works. Normally it'll have the opening temp stamped on it, you can test it in boiling water if you have a thermometer, or replace it. For an '88 the maintenance will be a factor, if it still has the original radiator. Depending on how often the coolant was replaced, you may need a flush to remove old deposits - and new coolant. The last thing will be the water pump, probably replaced by now??