Engine revs at idle!!

Hey there, got home from work today and paked the truck and as soon as I put it in park it started to rev. It is sitting at 1500 to 2000 rpms and wont go down! No engine light as of yet. Tried spraying wd40 on the throttle thought mabey it was stuck open but no luck....Any help? Thanks

95 Jimmy
4X4 4 door
4.3 L V6 Vin W

have you done anything to it recently, removed the intake, it could be a vacuum hose.

Hey there, got home from work today and paked the truck and as soon as I put it in park it started to rev. It is sitting at 1500 to 2000 rpms and wont go down! No engine light as of yet. Tried spraying wd40 on the throttle thought mabey it was stuck open but no luck....Any help? ThanksI had a reving condition with my '89 Jimmy. Mechanic found a gasket under the throttle body cracked. Apparently allows extra air to leak in and causes a lean condition, so the sensors tell it to add extra fuel to achieve proper mixture, so it revs. Thats the way the mechanic explained it to me anyway...

Found the problem. It was the Plenum gasket, was totally boken away,cleaned the EGR and new gasket as well, while I was in there!
PHEW!...lol