Maybe, maybe not. Could also be the valving. A bit of dirt can cause the valve to stick, and leak. Since these are usually mounted on the firewall, and usually draw air from around the shaft that the pedal pushes, and usually have a foam filter for the incoming air, they are getting fairlly clean air from inside the car. If yours is under the floor, be sure the filter is in place since that air is a bit dirtier down there, and a spec of junk could get into the valve causing your problem.
(However, if the idle goes up 300 then settles back down while you hold the pedal down, that's probably normal, depending upon the vacuum plumbing.)
JMHO,
Corley