quiz 4 Flashcards
The best repair of a broken wiring harness in an electronic fuel injection system is.
Complete replacement of the harness
A solid crimp splice
A well insulated, resistance free soldered splice
A crimp or solder splice as long as proper gauge wire is used
Complete replacement of the harness
To complete injector installation, put the following steps in the correct order.
__2__ Adjust the valves and injectors
__4__ Install rocker covers
__1__ Install the rocker shafts and related components
__5__ Bleed the fuel system
__6__ Test engine operation to confirm repairs
__3__ Install and adjust engine brakes
1-Install the rocker shafts and related components
__2__ Adjust the valves and injectors
__3__ Install and adjust engine brakes
__4__ Install rocker covers
__5__ Bleed the fuel system
__6__ Test engine operation to confirm repairs
Identify the basic troubleshooting path(s) from the list. (Select all that apply)
symptom based
fault code based
7 step process
SWAG method
fault code based
symptom based
Before removing rocker assemblies, it is critical to
mark all bolts so they go back exactly where they came from
back off adjusting screws
put engine on TDC 1
drain engine oil
back off adjusting screws
The fault code, displayed by the ECM, which must be repaired first is a(n):
historic code.
inactive code.
active code.
soft code.
active code.
When installing injectors, if the injector has fuel passage O-ring seals, you must lubricate them. Select all approved lubricants.
dish soap
engine oil
engine coolant
diesel fuel
manufacturers recommended lubricant
manufacturers recommended lubricant
engine oil
To measure the voltage drop across an electrical unit requires that:
it be taken out of the circuit.
current is flowing in the circuit.
battery voltage is reduced by a carbon pile.
current is not flowing in the circuit.
current is flowing in the circuit
A wiggle test is most often performed.
with the engine running
with the key on and engine not running
with the key off
when there are no codes present, only symptoms
with the key on and engine not running
When checking the resistance of the fuel shut-off solenoid the power must be:
turned on.
turned off.
flowing.
by passed.
turned off.
When installing an EUP, the proper procedure is
Bar the engine over with a barring tool so that the EUP tappet is resting on the lobe of the camshaft
Tap on the EUP with a dead blow hammer to seat it
Use a special puller to install the EUP
Use the mounting cap screws to evenly pull the EUP down
Use the mounting cap screws to evenly pull the EUP down
After locating a faulty temperature sensor on the engine a new sensor is installed according to manufacturer’s specifications. The next step to be taken should be:
check for proper battery voltage.
re-check oil level.
erase the fault code.
run the engine until normal operating temperature.
erase the fault code.
When replacing an EUI the internal fuel passages must be drained
to prevent engine damage
to prevent spilling fuel all over the customers equipment
to prevent damage to the electronic unit injector
to prevent your supervisor from yelling at you
to prevent engine damage
When removing an EUI, you can safely use
flat blade screwdriver
air pressure
T-bar puller
heel bar
heel bar
What do engine control diagnostics on a HEUI engine mean?
The measurement of electronic controlled engine output variables.
Diagnosis of the electronic system by a qualified service technician.
Entry data into the computer via a reader or PC keyboard.
A systematic procedure for finding faults in an engine control system.
A systematic procedure for finding faults in an engine control system.
On a unit with an electronic fuel injection system ECM, a fast charger
can be used anytime to start the engine
should not be used to start the engine
can be used to start the engine as long as all extra loads are shut off, like lights, heaters, etc.
should not be used to start the engine
The regulatory body that sets emission levels for North American diesel engines is the:
Environmental Protection Agency (EPA).
Diesel Protection Agency (DPA).
American Petroleum Institute (API).
Society of Automotive Engineers (SAE).
Environmental Protection Agency (EPA).
To prevent damage to the filter core, a diesel engine equipped with a DPF must use:
a bio-diesel / ethanol blend.
ultra low sulphur diesel fuel.
low sulphur diesel fuel.
a lubricity additive.
ultra low sulphur diesel fuel.
The cooling system on an engine equipped with the EGR system has a greater heat loading because the:
coolant slows down through the EGR cooler.
exhaust backpressure required for EGR holds more heat in the engine.
exhaust gases must pass through a water cooled heat exchanger.
cooling fan takes more power to turn.
exhaust gases must pass through a water cooled heat exchanger.
During a regeneration cycle, the exhaust outlet temperature of a DPF system will reach:
593°C (1100°F).
315°C (600°F).
715°C (1320°F).
1100°C (2012°F).
593°C (1100°F).
During regeneration, the DPF converts soot (carbon) emissions to harmless compounds of CO2 and NO. The DPF also traps ash which must be removed at periodic intervals by:
an off-vehicle cleaning process.
increasing the duty cycle (load) on the engine.
reversing the DPF filter core.
running the engine at high idle for 20 minutes.
an off-vehicle cleaning process.
An EUP system fuel injector is electronically controlled to determine the beginning and end of injection
True False
False
On an SCR system, DEF is sprayed in before the catalytic converter where it mixes with the hot exhaust gases and is converted into:
H2O and N2
ammonium nitrate.
CO2 and nitrogen.
nitric oxide
H2O and N2
If the soot loading on a DPF rises about 80%, the engine will:
undergo a severe de-rate and shutdown.
bypass the DPF until service is located.
initiate a forced manual regeneration.
operate with reduced fuel economy.
undergo a severe de-rate and shutdown.
The industry standard for DEF is a solution of:
41.5% urea and 59.5% distilled water.
50% urea and 50% distilled water.
32.5% urea and 67.5% distilled water.
60% urea and 40% distilled water.
32.5% urea and 67.5% distilled water.
The DOC in the exhaust after treatment module reacts with injected hydrocarbons to:
create additional heat for DPF regeneration.
reduce CO emissions.
reduce soot and sulphur emissions.
cool the PDF core after a regeneration cycle.
create additional heat for DPF regeneration.
The SCR system is primarily used to reduce emissions of:
particulates.
NOX.
sulphated ash.
CO2
NOX.
With the EGR system, introducing exhaust gas into the intake manifold is done to reduce the engine’s:
cooling system temperature and pressure.
intake manifold temperature and pressure.
fuel efficiency.
combustion pressure and temperature.
combustion pressure and temperature.
The __________________ and ________________ react and neutralize to water vapour and nitrogen gas.
ammonia molecules; nitrogen oxides
NH3 and CO2.
nitrogen; water vapour.
None of the above are correct
ammonia molecules; nitrogen oxides
A dosing valve is used on an engine equipped with a DPF. The purpose of this dosing valve is to supply:
hydrocarbons for the DPF operation.
urea for the catalytic converter.
hydrocarbons to react with the DOC.
flow through the DPF cooler.
hydrocarbons to react with the DOC.
To be compliant with EPA 2007 emission regulations, a highway tractor must be equipped with an EGR system and a:
SCR system.
wastegate turbocharger.
VDT.
DPF.
DPF.
