Fuel Delivery and Air Induction: Description and Operation

3.0L Engine:

The Sequential Electronic Fuel Injection Mass Air (SEFI-MA) system is a multi-point, pulse time, speed density fuel injection system. Fuel is metered into each intake port in sequence with the engine firing order in accordance with engine demand through the injectors mounted on a tuned intake manifold.

An Electronic Engine Control computer (EEC) receives signals from various engine sensors and computes the required rate of fuel flow to maintain an optimum air/fuel ratio throughout the entire range of engine operation. The computer then sends a command to the fuel injectors to meter the appropriate quantity of fuel.

The injectors are energized in pairs in the following sequence 1-2, 4-3, 5-6. Each group is activated once every other crankshaft revolution. The period of time that the injectors are energized (pulse width) is controlled by the ECA. Air entering the engine is measured by speed, manifold absolute presure and air charge temperature sensors.

The EEC engine control system determines and compensates for changes in altitude (i.e. from sea level to mountains). The system will also automatically compensates for the age of the vehicle and its uniqueness. For manual transmission vehicles it will also permit for push-starting if it becomes necessary.

The fuel delivery system consists of a high pressure electrical fuel pump mounted in-tank, high pressure fuel filter, fuel supply manifold, pressure regulator, fuel injectors, inertia switch, fuel tank and connecting lines.