Exam 78: Fuel-Injection Components and Operation

Technician A says that an idle air control valve controls the airflow past closed throttle plates. Technician B says that the idle air control valve is usually controlled by a stepper motor. Which technician is correct?

Technician A says that vehicles with electronic returnless fuel systems use pulse width modulation to power the fuel pump and maintain fuel pressure. Technician B says that the electronic returnless fuel system uses a power transistor to control the fuel pump. Which technician is correct?

Dampeners are used on some fuel rails to ________.

One type of injection system does that does not hold pressure when turned off is called a non-checking system. This is found on ________.

Which type of port fuel injection fires all the injectors at the same time, once per crankshaft revolution?