kaynos

4.2 awn with a stuck change over valve on the intake plenum. Facing the engine from the front there are 2 spring loaded shafts that run the length of the intake plenum, it's the left valve controlled by the diaphram vacuum motors that is seized. I can get it to move, but it doesn't spring back and it doesn't move easily.. Has anyone removed the intake and repaired this valve? I am assuming corrosion or rusting has siezed this. Is there any other cause.? Any guides out there to handle this problem?