I wonder anyone has experienced idle hunting problem with 1990 20V 90Q ! My 90Q hunts at idle (mainly when engine is cool). One dealer suggested that's the way they are - referring to all 1990 models. Another one suggested giving the idle valve a "bang", or taking the idle valve apart and lubricate it. Is this a user friendly operation ? Solomon Ngan 1990 90Q 20V 1984 5000S