Exam 30: Electronic Fuel Injection

A CPI (central multiport injection)fuel injection system for a six-cylinder engine has ______.

Which of the following is NOT an operating mode of a GDI (gasoline direct injection)engine?

Because modern engines heat up rapidly, heated oxygen sensors (HO₂S)are not needed.

Technician A says piezoelectric injectors rely on stacked crystals that expand when a voltage is applied. Technician B says piezoelectric injectors are slower acting than solenoid-type injectors. Who is correct?

Name five sensors that are used by the PCM to determine the proper injector pulse width.

Each fuel injector has a _____-wire connector.

Only _____ meets the requirements of OBD II regulations.

IAC (idle air control)valves are operated by a ______.

Which sensor synchronizes the firing of the injectors and determines when piston number 1 is on the compression stroke?

While discussing central port injection (CPI), Technician A says the poppet nozzles are opened by the computer. Technician B says the poppet nozzles are opened by fuel pressure. Who is correct?

All throttle body assemblies should be cleaned whenever the air filter is changed.

The ____________________ helps to maintain constant fuel pressure, reduces fuel noise, and maintains pressure during engine cool down.

Technician A says a throttle body may house one fuel injector. Technician B says a throttle body may house two fuel injectors. Who is correct?

Fuel trim can be monitored for diagnostic purposes.

OBD-II systems have only one O₂S (oxygen sensor)in the exhaust system, located after the catalytic converter (downstream).

Nearly all of today's diesel systems have a common rail injection system in which the injectors are directly controlled by the PCM.

Technician A says the oxygen sensor (O₂S)detects misfires by monitoring the amount of unburned fuel in the exhaust system. Technician B says a heating element inside the sensor allows the sensor to reach operating temperature quickly and to maintain its temperature during periods of idling or low engine load. Who is correct?

GDI [gasoline direct injection] systems allow engines to run at very lean air/fuel ratios and eliminate the need for EGR systems.

Technician A says the fuel pressure regulator in a PFI system senses manifold vacuum and  continually adjusts the fuel pressure to maintain a constant pressure drop across the injector. Technician B says the pressure regulator in a PFI system is designed to provide a constant pressure to the fuel injector throughout the range of engine loads and speeds. Who is correct?

Why are SFI injection systems required on modern vehicles?