Check to see if your fuel pressure regulator is leaking, its on the back side of the throttle body. Rebuild kits are cheap about $25.00 at your local parts store and takes about an hour. The hardest part is overcoming the spring pressure and tightening the screws when replacing the diaphragm.
http://www.autozone.com/fuel-deliver...?checkfit=true
https://www.youtube.com/results?sear...+body+rebuild+
Casey