Exam 12: Heui Injection Systems

While diagnosing the cause of a rough-running 2005 Ford Power Stroke engine, Technician A says that an incorrect injector calibration code will produce uneven cylinder contribution at idle. Technician B says that Gen II HEUI injectors do not use calibration codes. Who is correct?

What does an above-normal increase in the duty cycle of the PWM signal applied to the HEUI ICPR indicate?

What area of the fueling profiles represent(s) a sharp beginning of injection with a maximum quantity of fuel injected throughout the injection?

The maximum potential voltage supplied to a HEUI A or B injector is __________.

Which HEUI oil circuit does not pass through a filter, but instead connects the engine's main oil gallery to the reservoir?

Consider a HEUI fuel system. When the injector pulse width remains constant and the injection control pressure increases, which of the following changes will take place?

What prevents oil from draining back to the crankcase when the engine is not operated?

What is unique about the digital valve in the Gen II injector is its dependence on _____ to move the control valve.

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

Which of the following is NOT a variation of the HEUI (hydraulically actuated electronic unit injection) injector?

Technician A says an above-normal increase in the duty cycle of the PWM signal applied to the HEUI ICPR of a Cat C-7 engine indicates that the engine oil has thickened due to excessive soot loading. Technician B says a jumper plug in the wiring harness indicates to the engine's ECM that 10W-30 engine oil rather than 15W-40 oil is being used in the crankcase. Who is correct?

Which device uses an electrically operated spool valve that moves in response to the strength of a magnetic field to control injector oil pressure?

Current used to energize the injectors is stored in:

Pilot injection, also called split-shot injection, in HEUI B injectors is accomplished _______.

Technician A says that it is important to remove and drain the oil reservoir for a HEUI high-pressure pump when changing engine oil so that the oil does not contaminate the clean engine oil. Technician B says that it is not required or practical to drain the oil reservoir or accumulator when changing oil. Who is correct?

Later designs of HEUI (hydraulically actuated electronic unit injection) systems corrected the problem of short-circuit oil supply by using oil filtered by the engine to supply the:

Which of the following is the ability of the fuel system to adjust the quantity of fuel injected during the injection sequence?

The concept of eliminating the camshaft is simple: you use _____ to open and close the valve.

Pilot, main, and post-combustion injection events in the HEUI HIB-300 injector are controlled by the electrical signals to the:

While diagnosing the cause of a hard start/prolonged cranking complaint, Technician A says that the high-pressure oil between the high-pressure pump and the injectors should stay pressurized for days. Technician B says the oil pressure to the injectors should quickly drop to zero when the engine is shut off. Who is correct?