When working on a 350Z, be sure to open the car windows before turning off the battery power. Turn off your fuel system pressure, then unplug the negative battery terminal wire. Leave approximately 8 out of 10
Fuel Tank capacity for the job; if the tank is full now, empty it down to that level with the garden hose inserted carefully at the fuel filler neck. Remove the rear seat cushion. The fuel pump/fuel level sensor module lives in the right tank compartment and mixes the fuel pump inlet strainer, pump, fuel pressure regulator, and fuel level sensor together. Take off the steel access panel that holds four plastic screws. Disconnect the wiring connector from the top of the module unit. Disconnect the fast-release fuel supply line, then plug the other end to avoid fuel leak. Unscrew the bolts holding the retainer that holds the mounting flange, wipe around it, and lift the module with the fuel crossover tube out of the tank. Take out the fuel pump assembly module by disengaging its crossover tube connection. Twist the module as you pull it out to keep the fuel level sensor float arm from getting damaged. Take out the worn old O-ring from the mounting flange, and put on a new one, making sure the locator pins match up with their matching holes in the ring. Look at the fuel inlet strainer and make sure it's clean before you wipe it down or get a new one. Before working on the fuel level sensor module in the left side of the fuel tank, take off the metal access cover, disconnect the electric connector, scrub off dust around its retainer, loosen the retainer bolts. After taking out the fuel level sensor module, tilt it carefully so you do not hit the float arm. Leave behind the old mounting ring and get rid of its O-ring. Put the module back in place following the steps you used when taking it out.