1999 Ford Windstar wont stay running

Came back from a long trip last night, the van was running fine no noises, no issues. This morning my wife gets in and turns the key the van fires and promptly stalls out, Yes there is almost a full tank of gas. The van rarely goes under a half tank gas. I can keep it running at approx 1000 RPM but only with me maintaining pressure on the gas pedal. Not sure what the problem is because its not like a low idle cough out when id shuts down. Its much more like you just turned the key off? Any thoughts or where to start would be appreciated