Stalling

Engin stalls often at low rpm, hesitates on acceleration. Otherwise runs like a champ. Hate to take it to ford, can't do a big bill right now. Getting dangerous to drive it. Will start right up again. Help!

There are a number of things that can cause this.
What year is your Windstar?
Are all the routine maintenance items up to date?
If the Check Engine Light is on.....get the code(s) read.......many auto part stores will do this for you for FREE.....but make SURE to write down the actual numeric code so that you can come back here for specific help (Many codes are listed in a "sticky" post in this room).

Fuel pressure can cause this.
There is NO sensor that measures fuel pressure or flow.
What this means is that you will not get any code or Check Engine Light that tells you if this is an issue.
Check the vacuum hose that goes to the fuel pressure regulator.
Make sure that it is in place, and lot leaking, collapsed, etc.
Fuel FILTER, which is located under the vehicle....in front of the driver's side rear tire.....has it been changed recently?
Fuel Pump relays on newer, 1999 and newer, windstar.
Fuel pump getting weak.

Vacuum leaks....
Vacuum line (there are many) broken, cracked, loose.
Check vacuum line that goes from the big flex hose (between air filter and throttle body) and make sure that it is in place (front valve cover on 1995 through 1998, rear valve cover 1999 and newer).
Verify the vacuum line from PCV valve to throttle body......common for this to break down from the exposure to oil and heat.

Idle Air Control (IAC) valve sticking.....

Ignition issue.....Coil pack (cracks in body through which the high voltage arcs), spark plug wires, spark plugs.