why does 1992 astro van stall while driving?

A somewhat common problem from 92-94 Astro / Safari vans.

Take a look at your intake... if you have fuel injection that is underneath your aluminum intake manifold, you will want a fuel pressure gage. At the end of your day, hook a fuel pressure gage to your fuel rail, turn the key on (but not run), and your fuel pressure should go to 55psi. leave the gage on overnight. when you wake up, the pressure should not drop more than 5psi. if it does, you most likely have a leaky fuel injector "spider" (one injector, with 6 plastic legs and a regulator). you will need an upper intake gasket set (roughly $35), new injector unit (roughly $250), and a repair manual to walk you through the repair... it is not difficult with the right tools, but if you are uncomfortable with any of this - take it to someone who is qualified to do the repair.

Best of luck

~Joe

dirty fuel system most common try a bottle of fuel treatment

might fix it

because it does not have free candy painted on the side...