1994 Dodge Caravan Engine cranks normally but won't start

When the engine warm up after driving for about 20 minutes and the engine stall when I stop at the red light or stop completely. I have to wait for 15-20 minutes for engine to cool down before to start the engine again otherwise the engine won't start when it's hot. Now the car dies and won't start any more even the engine is cold. I did test the spark plugs and none of them has spark when the engine is cranking. Please advise.