Chapter 41 PowerPoint

Define these Technical Terms using the textbook:

1. accelerator pedal sensor

2. catalyst monitor

3. closed loop

4. direct injection system

5. fuel injectors

6. fuel pressure regulator

7. idle air control motor

8. indirect injection system

9. manifold absolute pressure (MAP) sensor

10. O2 sensor

Answer these discussion questions using the textbook:

1. Summarize the operation of oxygen sensors to control an engine air-fuel ratio.

Read the chapter summary below:

■ All electronic fuel injection systems can be divided into five subsystems: fuel delivery system, air induction system, sensor system, computer control system, and fuel metering system.

■ Atmospheric pressure (14.7 psi at sea level) affects the amount of fuel that must be injected into the engine.

■ Many sealed parts in and on an engine contain vacuum pressure.

■ The engine throttle valve controls air flow and engine power output.

■ An indirect injection system sprays fuel into the engine intake manifold. A direct injection system sprays high-pressure fuel into the engine’s combustion chambers.

■ A DEFI system has three injection modes: stratified charge mode, stoichiometric mode, and full power mode.

■ Two common types of electronic fuel injectors are solenoid fuel injectors and piezo fuel injectors.

■ Both low and high-pressure fuel injection systems require a fuel pressure regulator.

■ Both indirect injection systems and direct injection systems require a fuel rail to all injectors to obtain the same amount of fuel pressure and flow.

■ Fuel control sensors monitor various operating conditions and send information about these conditions to the engine control module.