flashing check engine light on 1997 Chevrolet Venture

check engine light started flashing. smelled light carbon burning or like a firework. turn off van and not will not restart

This is a sign that your engine is misfiring, and you want to avoid driving the vehicle in this condition, you will damage the catalytic converter, and they are very expensive!
Better have it looked at soon:
1 more answer
sounds like a cross between the converter , transmission and feul filter my 99 venture did the same thing took it in and thats what it came back as