Pressure pulsation damper containing a free floating spacer

A fuel system damper is provided having ahousing which is separated by a diaphragm into first and second chambers. The first chamber is sealed and contains a spring biased toward the diaphragm. The second chamber has an opening to allow fuel from a fuel rail to enter the damper and contact the diaphragm. The second chamber includes a radial shoulder that maximizes an effective area of the diaphragm. A spacer is disposed in the second chamber that engages the diaphragm to prevent the diaphragm from contacting the radial shoulder. The spacer maintains the diaphragm in a position to provide the maximum effective area of the diaphragm.