automotive technology 30-34

fps working range is what

.5v-5v

how much pressure does a typical EVAP pressure tester apply to the system during testing

0.5 psi

o2 sensor working range is what

0v-1v

above what temp do nitrogen atoms combine with oxygen atoms to form NOx

2300 degrees

Ten psi of turbo boost means the air is being fed into the engine at ________ when the engine is operating at sea level

24 psi

which of the following systems is designed to reduce NOx and has little or no effect on overall engine performance

EGR

what exhaust gases is typically measured during the I/M 240 test

HC NOx Co

The PCM checks for a closed throttle plate each time the engine starts. this becomes the base for all throttle settings and can be viewed by looking at the PID with the throttle closed. which of the following would not cause an abnormal reading and a higher than normal idle speed

a bad IAC valve

before an evap system can be pressurized with smoke a scan tool just be used to do what

close vent solenoid

which of the following would not cause a hard to start problem on the PFI engine

defective oxygen sensor

(gdi) gas directed injection allows engine to run with lean mixture and eliminates egr

false

all waste gates are controlled by the pcm

false

always pressurize fuel system before removing devices

false

digital egr valve has 3 solenoids

false

in GDI systems, the PCM controls fuel pressure through pulse width modulation of the electric high-pressure fuel pump

false

injector O-rings would be lubricated with silicone grease prior to installation

false

most late model systems use an AIR system

false

no start, during, or stalling can be caused by an EGRvalve that does not open

false

purge valves vent in open loop

false

the IM240 test measures the oxygen content or the exhaust

false

the signals from an air-fuel sensor are identical to those from a conventional oxygen sensor

false

which of these could cause a negative LFFT value?

faulty fuel regulator and leaking injectors

a restricted catalytic converter can cause all of the following except______

increased power at high speeds

as a catalytic converter begins to deteriorate, the signal from the post catalyst HO2S become _______ the signal of the pre catalyst HO2S

larger than

cpi is located in the lower or upper half or the intake manifold

lower

when the engine is idling, the pressure regulator provides___ fuel pressure compared to the fuel pressure at wide-open throttle

lower

what types of catalyst are typically used to reduce NOx and to oxidize HC and CO

reduciton catalyst oxidation catalyst

what problem may result from dirt buildup on an engines throttle plates

stalling at idle

a restrict exhaust system can cause _______

stalling, loss of power and backfiring

what is the first step in turbocharger inspection

start the engine and listen to the system

A vehicle is setting a lean exhaust code and has HO2S data shows the exhaust to be very lean. tech A says a malfunctioning AIR system may be the cause. Tech B says a clogged EGR may be the cause

tech A only

tech A says the AIR pump is driven by electricity. tech B says most modern vehicles have an AIR system.

tech A only

what is meant by pulse width of an injector

the length of time the injector is on

a mini-converter is used ____

to reduce emissions during engine warm up

a dual trace scope can be used to make sure the injectors are firing at the correct time

true

a rich air fuel ration causes HC emissions to rise

true

acoustic supercharging is designed into the intake runners

true

can a cpm command rich air/fuel mixture

true

diesel engines emit less hc, co2, co than a gas engine

true

diesel engines require higher fuel pressure than comparably sized gasoline engines

true

engine misfires can cause a catalytic converter to overheat

true

excessive oil consumption is caused by a plugged pcv

true

fuel injectors are electro mechanical device

true

hc and co emissions are highest when exhaust is cold

true

in a negative backpressure EGR valve, if the Ehaust pressure passage in the stem is plugged, the bleed valve remains closed

true

the PCV system prevents blowzy from escaping to the atmosphere

true

what manages turbo output by controlling about of exhaust gas entering the turbine housing?

wate gate

can you put a turbo and supercharger on the same engine

yes