120 QUESTIONS AND CORRECT

Advanced Engine Performance actual EXAM

120 QUESTIONS AND CORRECT

ANSWERS LAEST>>GRADED A+

The sensor that must be warmed up and functioning before the engine management computer will go to closed loop is the _____ - ANSWER****O2S

The voltage output of a zirconia oxygen sensor when the exhaust stream is lean (excess oxygen) is ____.

• ANSWER****Relatively low (close to zero volts)

The two internal chambers of a dual-cell wide-band oxygen sensor include - ANSWER****Air reference and diffusion

When the exhaust is rich, the PCM applies a ____ current into the pump cell. - ANSWER****Negative

A dual-cell wide-band oxygen sensor can be tested using a ____ - ANSWER****Scan tool Voltmeter Scope

If the air-fuel rations is 14.7:1, what is lambda? - ANSWER****1.0

If lambda is 0.98, this means the ______. - ANSWER****Air-fuel mixture is within 2% of stoichiometric Air-fuel mixture is slightly rich

Base pulse width is determined by _____ - ANSWER****Computer calculations Input from many sensors, except the oxygen sensor

The air at high altitude has ______. - ANSWER****21% oxygen

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In a speed density system, what does NOT need to be corrected for? - ANSWER****Oxygen in the exhaust system from the oxygen snesor

In a MAF system, which is correct? - ANSWER****The amount of EGR flow must be subtracted from the MAF sensor reading

Injector pulse width is measured in ______ - ANSWER****Milliseconds (ms)

What is NOT true about short-term fuel trim? - ANSWER****It can add and subtract a large amount of fuel

A Nissan is being checked, using a scan tool, and Alpha is 107. This means ______ - ANSWER****The PCM is adding fuel

A contaminated or defective MAF sensor is indicated if _____. - ANSWER****The fuel trim number follows the airflow

Tech A says that the fuel-pump relay is usually controlled by the PCM. Tech B says that a TBI Injector squirts fuel above the throttle plate. Who is correct? - ANSWER****Both Technicians A and B

Why are some fuel rails rectangular in shape? - ANSWER****Reduces noise

Which fuel-injection system uses the MAP sensor as the primary sensor to determine the base pulse width? - ANSWER****Speed density

Why is a vacuum line attached to a fuel-pressure regulator on many port fuel-injected engines? - ANSWER****To create an equal pressure drop across the injectors

Which sensor has the greatest influence on injector pulse width besides the MAF sensor? -

ANSWER****TP

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