Fuel Delivery & Control

Fuel delivery and control system consists of an electric in-tank fuel pump (integral part of fuel sending unit), fuel filter, fuel pressure regulator, fuel injectors, fuel rail and fuel delivery and return lines.

Fuel pump is energized by the fuel pump relay. The relay activates the fuel pump for 2 seconds when the ignition switch is turned to the "START" position. If the engine does not start within 2 seconds, the fuel pump relay will be de-energized. When the ECM senses that engine is running, it will. Again energize the relay. As a backup system to the fuel pump relay, the fuel pump can also be energized through the oil pressure switch circuit. If the fuel pump relay should fail the car would start when oil pressure built up, but only after prolonged cranking.

Fuel is supplied to engine through 8 sequentially pulsed (sprayed in engine firing order) injector valves located in fuel rails bolted to the intake manifold. A fuel pressure regulator, mounted in the fuel rail, maintains a constant pressure of 40-50 psi (2.8-3.5 kg) to the injectors under all operating conditions. Fuel pump is capable of supplying more fuel than is required even under extreme conditions. Excess fuel is routed back to the fuel tank via the fuel return line.

The timing of the sequential spraying of injectors is based on an ignition reference signal from the distributor. The ECM controls the amount of fuel metered through the injectors based on engine demand information.