General System

System Layout:

This vehicle is equipped with a 3.0 liter, 24 valve, DOHC (double overhead camshaft - each head) V-6 cyl. gasoline engine, and a computer controlled electronic fuel injection system (referred to as EGI - electronic gasoline injection). The system maintains an air/fuel mixture as close as possible to the ideal stoichiometric ratio, for all operating conditions. The computer monitors various sensors mounted on the engine, including an exhaust gas oxygen sensor, then uses this information to determine the amount of fuel needed. Fuel is supplied to the injectors at high pressure and the computer energizes the injectors (either all at once or in pairs) for varying lengths of time, depending on the amount of fuel required.

The intake air system, incorporates a feature, which Mazda refers to as the "Variable Resonance Induction System" (VRIS). This system uses a valve plate similar to a throttle valve to manipulate the air flow through the manifolds, taking advantage of resonant effects inside the manifolds. This systems help improve driveability and increase torque and horsepower across a broader operating range.


The primary fuel and intake components are covered in this section. For information regarding electronically controlled devices, the computer, and its functions, see Computers and Control Systems.

The fuel and intake system consists of the following:

Accelerator pedal and cable
Air cleaner, intake air ducts and associated parts
Bypass air control valve (BAC valve)
Fuel tank
Fuel pump
Fuel pump relay
Fuel filter
Fuel pressure regulator
Fuel rails
Fuel hoses
Fuel injectors
Pulsation damper
Shutter valve (Variable Resonance Induction System - VRIS)
Throttle body