Volcker was instrumental in getting things under control during Reagan's presidency. In his day he received as much praise as Greenspan does now for his leadership at the Fed.
Volker crippled the economy for several years by raising the fed rate to 20%. It was way too drastic of a measure that caused great pain to many people. Of course the economy rebounded after he eased, but I would hardly credit him with 'fixing' the economy he was largely reponsible for destroying. On the plus side, destroying the economy under Carter gave Reagan an easy landslide victory, but the Iran hostage situation may have given Reagan the victory anyways.
Ironically, the hard recession Volcker's initially high interest rates caused greatly contributed to Carter's defeat by Reagan.
Volker is an old fashioned mercantilist who thinks the balance of payments deficit matters more than IMHO it does. Greenspan and the Wall Street Journal disagree with him about that.