Exam 31: Fuel Injection System Diagnosis and Service

A pulse ____________________ injector uses high current to open the injector.

When looking at an O₂S [oxygen sensor] pattern on a lab scope, what should you be looking for?

Technician A uses a low-impedance test light to check for an injector pulse. Technician B uses a noid light to check the injector pulse. Who is correct?

Name the components in an ETC [electronic throttle control] system.

The activity of an O2 sensor is best monitored with a ______.

Technician A says a small leak in the air duct between the MAF and the throttle body will not cause a driveability problem. Technician B says a small intake manifold leak in a speed density system will not cause a driveability problem. Who is correct?

On an ETC [throttle-by-wire] system, the APP [accelerator pedal position] and TP [throttle position] sensors are checked using a(n) ____________________.

A/F ratio sensors are being discussed.Technician A says the output voltage of these sensors is much higher than a conventional O₂S [oxygen sensor]. Technician B say when the output of an A/F ratio sensor is looked at with an OBD-II generic scan tool, the voltage range will appear the same as a conventional O2S sensor, 0 to 1 volt. Who is correct?

All late-model engines use at least one ____________________ oxygen sensor.

If the IAC counts are below 16 on a fully warmed up engine, there may be a problem with a(n) ______.

When cleaning the injectors with a pressurized injector cleaner, prior to starting the engine, ______.

If an injector is not firing, how can you determine whether the injector is at fault or the PCM and wiring are the fault?

Which of the following would NOT cause the fuel trim to be out of range?

If the injectors and their electrical harness are visible but cannot be accessed without removing the upper intake manifold, injector operation can be checked by using a(n) ____________________.

When the system is running in open loop mode, the STFT value should be ____________________.

When viewing injector patterns on a lab scope, the injector pulse end with a ______.

Technician A says if a lean condition caused by a vacuum leak, restricted injectors, dirty MAF, clogged fuel filter, or bad fuel pump exists, the LTFT will have a negative number. Technician B says when the O2 sensor has a rich signal, the STFT goes lean to adjust the air/fuel ratio. Who is correct?

While testing, a good pressure regulator diaphragm will hold ____________________.

What is the correct procedure for checking an oxygen sensor with a voltmeter?

Never turn on the ignition switch when any fuel system component is disconnected.