93 Plymouth Voyager issue

Here's something to try. Unplug the vacuum hose from the fuel pressure regulator and plug it, then see if it runs better at higher speeds. If it does, suspect a collapsing pickup screen in the gas tank. The clue is it runs better now when you accelerate. That is when the lowest volume of fuel must pass through that screen. A plugged screen will often cause stalling during coasting. That's when fuel volume is at its highest; the restriction causes fuel pressure to drop too low.