Aerostar will not start

[awvickers]

While on the road doing about 50mph my 1993 ford aerostar began to slow down and came to a complete atop. I was able to pull to the side of the road. While sitting there I tried to start it back up. It would not start. Previous problems I encounter with this vehicle included the water pump, heating coil, and thermostat. And I also notice that more and more white smoke is exhausted out of the tail pipe during the initial startups.
Could you tell me what to do about my current problem?