Exam 30: Electronic Fuel Injection

The length of time an injector is energized is called the ____________________ width.

To prevent fuel boiling in the TBI assembly, the fuel pressure is kept high.

Explain the major differences between throttle body injectors and port fuel injectors.

Fuel injectors are ____________________ top and bottom devices.

The IAC system uses a ____________________ motor to retract or extend the IAC valve.

A sudden increase in TP voltage tells the PCM to _____ to prevent hesitation and stumbling during acceleration.

What is the difference between open loop and closed loop mode?

When does a GDI (gasoline direct injection)system run in lean burn mode?

While cranking a fuel injected engine and holding the accelerator to the wide-open throttle position, the air/fuel mixture will be ______.

In most TBI systems, the fuel pressure is maintained at _____.

Describe the purpose of a manifold absolute pressure (MAP)sensor.

Technician A says throttle-by-wire systems (ETC)eliminate the need for a cruise control actuator. Technician B says ETC also allows the PCM to be more effective when limiting engine and vehicle speeds. Who is correct?

The auxiliary air valve is controlled by the PCM.

Fuel injectors may be controlled ______.

The fuel pressure regulator can be located _____.

Technician A says in a returnless fuel system, the pressure regulator is mounted on the fuel rail. Technician B says in a returnless fuel system the pressure regulator, fuel sender, and pump assembly are combined in one unit inside the fuel tank. Who is correct?

To meet OBD II regulations, an updated version of the central port injection (CPI)system uses individual injectors for each poppet nozzle. This system, called central sequential fuel injection (CSFI)allows each injector to be shut off in the event of a misfire.

Identify the purpose and two designs of mass airflow sensors.

The ____________________ system controls idle speed by opening and closing a bypass passage in the throttle body in response to commands from the PCM.

The throttle body of a port fuel injected engine may include any of the following components EXCEPT: