Medium diesel engines final exam

program 4-digit CAL code to ECU

After replacing an EUP unit in an EUP engine, which of the following should be performed to ensure balanced fueling? a. program 2-digit alpha code to ECU b. program 4-digit CAL code to ECU c. run a cylinder cut-out test d. reset the governor type to VS

seven times

By how much does a HEUI amplifier piston exceed the sectional area of the pumping plunger by? a. one time b. four times c. seven times d. five times

485 psi - 4000 psi

HEUI actuation oil pressures fall into which of the following range of values? a. 150-300 psi b. 485 psi - 4000 psi c. 5000-24,000 psi d. 30-60 psi

hydraulically using engine oil as medium

How are fuel injection pressures created within a HEUI injector? a. hydraulically using engine oil as medium b. mechanically using a swash plate pump c. hydraulically using fuel as medium d. mechanically using a cam profile

engine control module (ECM)

How is effective pump stroke managed in a HEUI fuel system? a. mechanical governor b. road speed governor programming c. throttle position sensor angle d. engine control module (ECM)

fuel

How is the Mack Trucks V-MAC III engine ECU cooled? a. coolant b. internal fan c. fuel d. ram air

four

How many ECM actuators are located on the rail of a Cummins ISX engine using HPI-TP fuel management? a. two b. four c. six d. three

six

How many digits are there in an IQCC code? a. two b. four c. eight d. six

six

How many electronic unit pumps (EUPs) are required to fuel an in-line, 6 cylinder engine? a. one b. three c. six d. two

one

How many high pressure pumps are required to fuel an inline 6-cylinder, ACRS-fueled engine? a. Two b. One c. Six d. Three

one

How many high pressure pumps are required to fuel an inline 6-cylinder, CR-fueled engine? a. One b. Three c. Six d. Two

two

How many pistons are used in the DD-Series ACRS piston pump? a. Two b. Six c. Three d. One

three

How many plungers are used in the high pressure section of a Bosch radial piston pump? a. Two b. One c. Six d. Three

Technician A only

Technician A says that CR EHIs with piezo actuators respond faster to energization by the injector drivers than those with solenoid actuators. Technician B says that current CR EHIs using piezo actuators tend to be slimmer and more compact than those with solenoid actuators. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Both A and B

Technician A says that Cummins ISX, HPI-TP injectors are mechanically actuated with no integrated electronic components. Technician B says that injection timing in an HPI-TP injector is variable and managed by the engine ECM. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Both A and b

Technician A says that EHI opening is soft. Technician B says that EHI opening pressure is controlled by the ECM. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Technician A only

Technician A says that adaptive trim (A-Trim) evaluates and corrects EHI fuel flow at set intervals to ensure balanced cylinder fueling. Technician B says the A-Trim feature makes initial fuel flow programming (E-Trim/ QR-codes/ Cal-codes) unnecessary. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Technician A only

Technician A says that an EHI with a Piezo actuator is capable of breaking up a single injection cycle into up to 7 separate pulses. Technician B says that during a CR EHI multipulse injection cycle, the pressure rises through each successive pulse. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Technician B only

Technician A says that an EUP fueled engine must use a camshaft that rotates in the same direction as the crankshaft. Technician B says that EUP roller lifters ride directly on the cam profiles that actuate them. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Neither A nor B

Technician A says that an advantage of CR-EHIs is that they are less susceptible to problems caused by contaminated fuel than other types of fuel injector. Technician B says that when a CR-EHI fails due to contaminated fuel, the problem can be usually rectified by disassembly, cleaning, and reassembly. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Both A and b

Technician A says that an advantage of EHIs over standard hydraulic injectors, is the absence of injection lag. Technician B says that EHIs are capable of multipulse injections within a single cycle. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Neither A nor B

Technician A says that desired rail pressure in a ACRS fuel system is signaled by the QCV. Technician B says that actual rail pressure in an ACRS fuel system is calculated by the ECM. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Technician B only

Technician A says that fuel delivery timing in diesel CR fuel systems is limited by cam profile. Technician B says that a major advantage of diesel CR systems is their ability to manage fuel injection pressures without regard to engine rpm. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Both A and b

Technician A says that in a diesel CR fuel system, the rail supplies all of the injectors required to fuel the engine. Technician B says that the rail pressures in a diesel CR fuel system are widely variable. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Technician A only

Technician A says that in an ISX engine using HPI-TP injectors, one metering actuator is responsible for fueling the front three cylinders and another for the rear three. Technician B says that on the same engine, one timing actuator manages timing on cylinders #2 and #5. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Technician A only

Technician A says that the Caterpillar HEUI system is a full authority, computer controlled engine management system. Technician B says that some HEUI fueled engines are managed hydromechanically. Who is right? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Both A and B

Technician A says that the IQCC for each DD-Series HADI must be reprogrammed to the MCM every time an injector is changed out. Technician B says that failure to reprogram a HADI IQCC on change-out can result in unbalanced engine fueling. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Technician A only

Technician A says that the actuation voltage used to drive CR electrohydraulic injectors (EHIs) is typically around 100 volts when they use solenoid actuators. Technician B says that actuation voltage for EHIs that use piezo actuators is usually much higher than 100 volts. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B.

Both A and b

Technician A says that the general operating principles of Caterpillar and Siemens built HEUIs are identical. Technician B says that the Siemens HEUI is smaller and lighter than the Caterpillar equivalent. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

Both A and B

Technician A says that the when a HADI is operated in non-amplification mode, the resulting injection pressure should be roughly equivalent to the ACRS rail pressure. Technician B says that when the HADI is operated in amplification mode, ACRS injection pressure is more than double the rail pressure. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B

all of the above

What are the main advantages of using EHIs in place of hydraulic multi-orifii injectors in an EUP fuel system? a. soft opening pressures b. faster response times c. elimination of the collapse phase d. all of the above

rail pressure control valve

What component is used to control the actual rail pressure of a CR diesel fuel system? a. rail pressure sensor b. accumulator c. rail pressure control valve d. EHI solenoid

quantity control valve (QCV)

What component is used to control the rail pressure of an ACRS diesel fuel system in any given moment of operation? a. rail pressure sensor (RPS) b. rail pressure regulator (RPR) c. EHI solenoid d. quantity control valve (QCV)

time EUP solenoid is energized

What controls the length of plunger effective stroke in a EUP system? a. time EUP solenoid is energized b. time nozzle is open c. tappet stroke d. cam profile

ECM pulse width modulated signal

What controls the linear position of the injection pressure regulator (IPR) in a HEUI fuel system? a. V-Bat (battery voltage) b. fuel pressure c. ECM pulse width modulated signal d. oil pressure

cam profile

What determines actual plunger stroke in any EUP fueled engine? a. radial dimension of EUP roller bearing b. ECU drivers c. cam profile d. plunger radial dimension

actuation oil pressure value

What determines how fast a HEUI amplifier piston is driven through its stroke? a. poppet spill flow area b. actuation oil pressure value c. engine rpm d. duration HEUI control solenoid is energized

actuation oil pressure

What does an injection pressure regulator (IPR) valve control? a. time of HEUI duty cycle b. length of HEUI effective stroke c. fuel injection pressure d. actuation oil pressure

5000 psi

What is a typical NOP value in a HEUI injector nozzle? a. 24,000 psi b. 5000 psi c. 4000 psi d. 3000 psi

fuel flow code to balance injectors

What is another way of describing the HADI injector quantity compensation code (IQCC)? a. fuel flow code to balance injectors b. leak-off pressure differential c. peak injection pressure rating d. rail pressure

115 volts

What is the actuation voltage typically used to energize HEUI solenoids? a. 75 volts b. 115 volts c. 50 volts d. 12 volts

connects the rail high pressure pipes to the EHIs through the cylinder head

What is the function of the quill tube used in many diesel CR systems? a. connects the rail high pressure pipes to the EHIs through the cylinder head b. vents the fuel tank to atmosphere c. connects the CR high pressure pump to the rail d. connects the transfer pump to the secondary filter

engine oil

What is the hydraulic pumping medium used to produce injection pressures in the HEUI fuel management system? a. engine oil b. engine coolant c. fuel d. hydraulic oil

5000 psi

What is the specified NOP value on a pre-2007 Mack E-Tech, EUP fueled engine? a. 26,000 psi b. 100 psi c. 2000 psi d. 5000 psi

pulse width modulated signal

What is used to switch a HADI used in a typical ACRS fuel system? a. Hydraulic distributor head b. Pulse width modulated signal c. Fuel volume in accumulator d. Analog voltage charge

pulse width modulated signal

What is used to switch an electrohydraulic injector (EHI) used in a typical CR fuel system? a. Pulse width modulated signal b. Analog voltage charge c. Fuel volume in accumulator d. Hydraulic distributor head

timing pin

What is used to time a Caterpillar CR fuel system high pressure pump to the engine? a. timing pin b. spill timing c. electronic timing d. high pressure phasing

oem timing wedges

What must be used to time the camshafts in a Cummins ISX engine? a. OEM calibration indices b. OEM timing wedges c. dial indicator d. thickness gauges

Insite software

What must be used to troubleshoot the Cummins ISX, HPI-TP fuel system? a. OEM service literature b. CELECT Plus software c. a digital multimeter (DMM) d. INSITE software

drain the fuel manifold

What should be done before removing an EUP from an engine cylinder block? a. drain the fuel manifold b. clamp the EUP retraction spring c. remove the camshaft d. drain the engine oil

amplifier

What term does Navistar use to describe what Caterpillar calls an intensifier piston? a. magnifier b. amplifier c. proportioner d. enhancement

E-trim

What term is used by Caterpillar on their CR EHIs to code their injection quantity calibration data for programming to the ECM? a. Set point b. E-Trim c. Cal code d. quick response (QR) code

HPI-TP

What type of fuel system is used on the 2010 Cummins ISX engine? a. XPI b. EUI c. CAPS d. HPI-TP

Hydraulically-amplified diesel injector (HADI)

What type of injector is used in a Detroit Diesel ACRS system? a. electrohydraulic injectors (EHIs) b. Multi-orifii injectors c. Poppet injectors d. Hydraulically-amplified diesel injector (HADI)

Electrohydraulic injectors (EHIs)

What type of injectors are used in a typical diesel CR system? a. Poppet injectors b. EUI's c. Electrohydraulic injectors (EHIs) d. Pintle injectors

swash plate

What type of pump is used in the HEUI system to raise the engine oil pressure to actuation pressure values? a. plunger type b. external gear c. vane d. swash plate

pulse width modulated

What type of signal is used to control Cummins HPI-TP timing and fueling actuators? a. AC b. spiked DC c. pulse width modulated (PWM) d. data bus

48 volts

What voltage is used to actuate Siemens HEUI in Navistar applications? a. 48 volts b. 115 volts c. 5 volts d. 12 volts

replace the high pressure line

When a CR high pressure line is removed for any reason, which of the following steps is required practice by many engine OEMs? a. torque the line nuts to spec b. remove and replace the line nuts c. replace the high pressure line d. dress the sealing nipples on a grinder

actuation oil cannot enter the HEUI

When a HEUI is not energized, which of the following is true? a. actuation oil cannot enter the HEUI b. actuation oil circulates in the HEUI c. actuation oil acts only on the intensifier d. fuel does not enter the HEUI

30-60 psi

When a plunger type fuel transfer pump is used with HEUIs, what are typical charging pressure parameters? a. 30-60 psi b. 150-320 psi c. 100-150 psi d. 75-110 psi

amplifier piston

When actuation oil enters the HEUI, which of the following components does it act directly on? a. fuel pump chamber b. fuel pressure regulator c. amplifier piston d. nozzle valve

secondary filter inlet

When attempting to prime a Mack Trucks E7 EUP fuel subsystem, which of the following fittings should be cracked before actuating the hand primer pump? a. primary fuel filter outlet b. secondary filter inlet c. fuel tank breather vent d. ECU cooling plate inlet

engine oil

When installing an EUP to an engine cylinder block, how should the O-rings be lubricated? a. engine oil b. install dry c. silicone d. fuel

IFSM

Where are the electronics that manage the timing and metering actuators housed? a. InSite module b. IFSM c. ECM d. vehicle bulkhead

VCO, multi orifii

Which of the following best describes the type of injection nozzle used on a HEUI? a. pintle b. electrohydraulic c. VCO, multi orifii d. sac type, multi orifii

inline piston

Which of the following best describes the type of pump used with the DD-Series ACRS fuel system? a. Radial piston b. Inline piston c. Rotary distributor d. Opposed plunger

radial piston

Which of the following best describes the type of pump used with typical Bosch CR fuel systems? a. Radial piston b. In-line plunger c. Rotary distributor d. Opposed plunger

the seats deform to seal when initially torqued

Which of the following best explains why some OEMs state that the high pressure pipes used on CR systems should not be re-used? a. the seats deform to seal when initially torqued b. the engine warranty will voided c. it is more profitable to the OEM to sell as many parts as possible d. the line nut hex is easily rounded out

single slab

Which of the following correctly describes the cylinder head(s) used on a pre-2010 ISX HPI-TP fueled engine? a. two over 6 cylinders b. three over 6 cylinders c. one per cylinder d. single slab

secondary filter

Which of the following fuel sub-system components is NOT under suction in a V-MAC III EUP fuel system? a. ECU b. secondary filter c. fuel tank d. primary filter

twin overhead with separate functions

Which of the following is true of the camshafts used in a pre-2010 Cummins ISX engine? a. twin overhead with separate functions b. double block-mounted c. chain driven d. twin overhead with identical functions

2:1

Which of the following ratios represents the amplification ratio used on the DDC DD-Series ACRS engines? a. 4:1 b. 2:1 c. 3:1 d. 7:1

rail

Which of the following serves a role as an accumulator in an ACRS fuel system? a. Rail b. Hydraulic head c. Amplifier chamber d. Pump chamber