My name is Thom. Hello to everyone here. My son hooked up a new battery in his 1990 Chevy Astro van backwards and smoke rolled from under the hood. He said it seemed to come from the top area of the engine. After hooking the battery up correctly, the engine will turn over, however, it will not start. I do not smell any gas at all while cranking the engine. However, there is fire to the plugs. Checked the fuses. The ECM-B fuse was blown, changed that one out. However, that didn't change the situation. Any help here would be appreciated.