idle fluctuates till eventual stall or it idles around 1500 rpm on 2001 Ford Windstar

replaced isolater grommets, crank and cam position sencors, egr valve iac valve, tps sensor, maf sensor, upper and lower intake gaskets and replaced lower intake with a used lower intake. i would like to the the used lower intake didnt have the same problem as the original. any other ideas or suggestions?

Asked by for the 2001 Ford Windstar