The Datsun 240z came with a mechanical diaphragm fuel pump, running off an elliptical gear bolted to the front of the camshaft timing gear. The Datsun 260z was equipped with a mechanical fuel pump and also with an electrical fuel pump . The electric fuel pump was located in the rear with fuel tank, it did not turn on until the engine reached 400rpms. The flow rate was less for the electric fuel pump but the pressure was much higher. The 280z and future 280ZX used an electric fuel pump only, the higher pressure supplied was for the Electronic Fuel Injectors. The lower fuel flow rate was because of a higher efficiency of fuel supplied to system, minimizing fuel being pumped back to tank.