I suppose that depends on what you can afford, and if there's any sentimental value to this Windstar. You at least know what ISN'T wrong with the vehicle. If you buy something else, you would be starting over at square one. Although if what you replace this with runs well at the time, you will be ahead from that perspective.
There's a good chance the Windstar will nickel and dime you for the remainder of your ownership, and even if you put the money and time into fixing it and making it reliable, it's unlikely you'll get that money back out of it if you sell it within the next couple of years.
-Rod