When I start my vehicle it stays on, but then stalls. It smokes a lot and pops when I press on the gas pedal, I have to pump the gas twice for it to drive forward.
What color is the smoke that is coming out of the back of your van? The color of smoke can help tell you what is going on. If the smoke is a bluish color your engine is burning oil. If it is black that means there is too much fuel. If it is white that means coolant is being burned during combustion. I would suggest that you take this information to a certified mechanic who can diagnose why your vehicle is smoking a lot and running poorly.