Exam 12: Heui Injection Systems

Which part of the Gen II injector event begins with the spool valve in the closed position, preventing oil from entering the injector?

Which of the following conditions is indicated when engine oil contaminates the fuel tank of a vehicle with a HEUI engine?

What injection strategy delivers fuel in two distinct events during one combustion cycle?

Which diesel injection system is capable of pressurizing fuel independent of engine speed?

Which of the following is a unique feature of the HEUI HIB-300 injector?

What part of the HEUI (hydraulically actuated electronic unit injection) A and B split-shot injector atomizes and distributes fuel into the combustion chamber?

This modular construction feature of HEUI (hydraulically actuated electronic unit injection) system components permits HEUI adaption to a specific engine application by simply changing the:

Consider an engine with a HEUI fuel system. Which of the following problems will most likely cause a hard start/prolonged cranking condition only when the engine is hot?

What level of voltage do Gen II injectors require?

Caterpillar uses a removable electrical jumper plug on C-7 and C-9 engines to correct actuation system variables when using either:

Technician A says acoustic wave attenuation (AWA) fittings in the oil manifold of some Gen II HEUI engines reduce irregular combustion noise. Technician B says split-shot injection reduces combustion noise. Who is correct?

Which of the following HEUI (hydraulically actuated electronic unit injection) injectors does not use split-shot- or pilot-injection capabilities?

What change generally takes place when the length of the pulse width to an injection control pressure regulator (ICPR) is increased?

If Gen II injectors misfire, fail to deliver the correct quantity of fuel, are worn out or contaminated, or have sticking control valves, then they may need to be:

Technician A says that higher levels of detergents and antifriction additives are needed by HEUI engines to maintain stable injection control oil pressure. Technician B says that antifoaming agents are more important than additional antifriction and detergent additive for a smooth and efficient engine operation. Who is correct?

When replacing a HEUI (hydraulically actuated electronically controlled unit injector) injector, you inspect the condition of the inlet injector O-rings and find it nicked. Which of the following actions do you take?

Technician B says that Gen II injection timing can be varied by changing the specific time during crankshaft rotation to cycle the open and close coils. Technician B says to change the rate of fuel delivery, the oil pressure to the injector is electronically varied by a variable resistor. Who is right?

When investigating the cause of frequent injector failures on a HEUI B engine, Technician A says a likely cause could be engine oil contaminated with dirt entering the engine through a leaking air filter. Technician B says that condition will not cause injector failure, because the oil is filtered before supplying the injectors. Who is correct?

Fuel supply pressure is regulated to:

While discussing the purpose of pilot injection, also known as split-shot injection, Technician A says HEUI injectors use it to reduce NOx emissions. Technician B says PRIME metering can reduce combustion noise. Who is correct?