The Mazda Electronic Gasoline Injection (EGI) system is a computer controlled, port-type fuel injection system used on 1984–89 RX-7 models equipped with the 13B rotary engine. Fuel is metered to the engine by two solenoid-type injectors that open and close in response to signals from the Electronic Control Unit (ECU). By varying the amount of time the injectors remain open, the ECU precisely controls the fuel mixture according to data on engine operating conditions provided by various engine sensors.
The EGI fuel supply system consists of the fuel tank and lines, fuel filter, electric fuel pump, pulsation damper, fuel pressure regulator, fuel delivery manifold and two solenoid-type fuel injectors. A check and cut valve releases excessive pressure or vacuum in the fuel tank to the atmosphere and prevents the loss of fuel if the vehicle overturns. The fuel system is constantly under pressure, which is regulated to 37 psi (255 kPa).
The fuel pump provides more fuel than the injection system needs for normal operation, with excess fuel being returned to the tank via the fuel return line. The fuel pump is a roller cell type, which is capable of providing 49–71 psi (338–490 kPa) of pressure as measured at the pump outlet.
On 1984–85 models, the pump is located near the fuel tank, under a protective shield on the underbody of the vehicle. The pump connector is located under the storage compartment located behind the driver's seat. On 1986–89 models, the pump is mounted inside the fuel tank.
The pressure regulator and pulsation damper are mounted on the fuel delivery manifold, located under the dynamic chamber just above the injectors. The operation of the fuel delivery system is controlled through the main relay mounted in the engine compartment next to the master cylinder, with power feeding through a fusible link located near the battery.