engine shaking badly

[slowpoke]

have rocker cover off 3 jake rocker moving when idling others are stationary push in center of solenoid 3 front jakes come on they all move look good rears are the same checked top end set still same 15 and 28 . push down on roker bounces back up to detent 2 of them push back onto cam and stays there until engine runs they are two that don't move while idling. so should rockers move will idling or should they be stationary