If you mean you can move the lever w/o it engaging at all (pulling cable), flood it with WD40, carb n' choke, any solevent that makes you real dizzy, 'specially when you're inhaling it from a plastic bag. If you're lucky it'll start working again. Otherwise, yes, you probably need a new one.

If it moves and pulls cable, it probably needs an adjustment, maybe new cable and housing.