Exam 27: Heui Fuel Systems

Which of the following engine OEMs used the HEUI fuel management system up to the EPA 2007 model year?

What controls the linear position of the injection pressure regulator (IPR) in a HEUI fuel system?

What determines how fast a HEUI amplifier piston is driven through its stroke?

How are fuel injection pressures created within a HEUI injector?

If Navistar HEUI actuation oil pressure is specified at 3000 psi at a given moment of operation, what are injection pressures likely to peak at?

Where is the HEUI system hand primer pump usually located on both Caterpillar and Navistar engines?

What is used in the ECM to increase the HEUI solenoid actuation voltage?

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?

What determines the emitted droplet sizing from a HEUI?

In what year was the Siemens HEUI introduced on Navistar built engines?

What happens in the HEUI fuel pump chamber when the plunger PRIME recess registers with the pump chamber spill port?

Which of the following engine OEMs uses the HEUI fuel management system on post-2010 highway diesel engines?

When a plunger type fuel transfer pump is used with HEUIs, what are typical charging pressure parameters?

When actuation oil enters the HEUI, which of the following components does it act directly on?

Technician A says that actuation oil is supplied to the HEUIs in parallel. Technician B says that HEUI actuation oil pressure in managed by the ECM. Who is correct?

What is a typical NOP value in a HEUI injector nozzle?

When a HEUI solenoid is de-energized, which pressure field collapses first?

What is the term Caterpillar use to describe the pilot injection feature of later model HEUIs?

What is the actuation voltage typically used to energize HEUI solenoids?

What term does Navistar use to describe what Caterpillar calls an intensifier piston?