I have a 91 civic dx and it over heats and now when I start it it dies in 30 sec before I had a problem with it over heating and I replaced the motor it was the same 1.5 dx motor and it sill over heats any thought to what might be the problem with the over heating or the car dying the radiator doesn't come on at all and I have replaced almost everything

Over heating could be caused by mineral build up clogging the veins of the radiator. Only use a 50/50 mixture of antifreeze and distilled water, which should be changed every 2 to 3 years. You will likely have to replace the radiator.

For the running problem you are experiencing, I would go over the whole electrical system. Check all under-hood and under-dash fuses with a test light or multimeter. Also, check for any codes being thrown. Have you recently replaced the spark plugs, distributor cap, igniter, coil, rotor, spark plug wires, main relay, adjusted idle rpm, and checked timing?