What is your question?
·
·
What is your question?
my van cuts in an out an has hevy black smoke coming from tail pipe and it is realy bad on gas

A diagnostic test only starts with reading codes. A 1991 vehicle is very limited in diagnostic codes compared to a current year model. Some good manual testing of fuel pressure, air flow, monitoring oxygen sensor performance and barometric pressure is a good start.
its not showin any codes