Electronically Controlled Fuel Injection Systems

Question 1

What is the purpose of the ECM cooling plate?

Answer 1

Allow fuel to flow through the ECM and cool it

Question 2

What is the purpose of the fuel transfer system?

Answer 2

Supply the electronically controlled injector with clean, cooled, de-aerated fuel at the correct pressure and temperature

Question 3

Electronic Unit injectors

Answer 3

Pressure built by the camshaft rocker pushing down on the top of injector. The ECM then decides how long to open the injector, and when it needs to be opened.

Question 4

the three main sensors monitored to control EUI injection processes are?

Answer 4

Throttle position
Intake manifold pressure
Engine speed and timing

Question 5

EUI injection process is broken down into what for stages?

Answer 5

Pre-injection
Injection
End of injection
Fill

Question 6

EUI pre injection

Answer 6

The cam lobe starts to force the fuel injector plunger downward, the solenoid is de-energized, poppet valve is open and fuel is forced out of injector by the plunger into the fuel supply passage

Question 7

EUI injection

Answer 7

Solenoid is energized, poppet valve closed, nozzle opens at around 4500 PSI, fuel is injected. S

Question 8

EUI end of injection

Answer 8

Solenoid is de-energized and poppet valve opens by spring pressure

Question 9

EUI fill

Answer 9

The injector plunger moves upward and the injector is filled with transfer pressure

Question 10

Calibration code number

Answer 10

Identifies fuel delivery variations that exist between each fuel injector

Question 11

HEUI system operation is dependent on the interaction between what sub-systems?

Answer 11

Electronic control
Fuel transfer
Hydraulic actuation
HEUI injectors

Question 12

HUEI injectors

Answer 12

Are hydraulically actuated to create injection pressure and deliver fuel to each of engines combustion chambers

Question 13

HUEI hydraulic actuation pressure varies from?

Answer 13

870 - 3500 PSI

Question 14

HUEI actuation pressure is controlled by what?

Answer 14

Injection actuation pressure control valve, ECM, And the injection actuation pressure sensor.

Question 15

What is size ratio of intensifier piston?

Answer 15

Top is 6-7 times larger then plunger

Question 16

HUEI injection operation consists of what 5 stages?

Answer 16

Pre-injection
pilot injection
delay period
main injection
end of injection

Question 17

The HPCR system consists of what components?

Answer 17

High pressure pump
Rail pressure control valve
Rail pressure sensor
Common fuel rail
Pressure limiting valves
High pressure lines
Injectors

Question 18

HPCR high pressure pump builds pressure of what?

Answer 18

Module says 4000 - 26000 PSI

Question 19

HPCR pressure limiting valve will open if rail pressure reaches what?

Answer 19

2000 - 3000 PSI over the normal operating pressure

Question 20

What is the purpose of a flow limiting valve?

Answer 20

Shut off fuel flow to the injector when it exceeds about 1.5 times the normal flow rate

Question 21

Energizing the solenoid in a HPCR injector creates what?

Answer 21

A pressure differential in the injector that allows the high pressure pushing up to over come the spring and low pressure on top of intermediate valve, the nozzle opens and fuel enters combustion chamber

Question 22

Electronic unit injector are actuated by?

Answer 22

A mechanical injector drive mechanism

Question 23

What is the purpose of the poppet valve in the electronic unit injector?

Answer 23

Controls fuel flow through the injector to begin and end injection

Question 24

The amount of fuel injected by an electronic unit injector is typically expressed as pulse width. Pulse width can be measured in?

Answer 24

Degrees of crankshaft rotation
Percentage of fuel
mm of fuel

Question 25

A HUEI fuel injection system involves a high pressure engine oil hydraulic system and a _____ pressure diesel fuel system.

Answer 25

Low

Question 26

HEUI injectors are controlled by the ECM to determine?

Answer 26

BOI EOI Fuel metering

Question 27

What are the 5 stages of the HEUI fuel injection process?

Answer 27

``` Pre-injection Pilot injection Delay period Main injection End of injection ```

Question 28

To begin the injection process in a HEUI injector, the poppet valve must be _________ by the injector solenoid

Answer 28

Opened

Question 29

T/F The HEUI fuel injector is filled with diesel fuel during the end of injection stage?

Answer 29

True

Question 30

What component does the high pressure oil act on inside of the HEUI injector?

Answer 30

Intensifier piston assembly

Question 31

The HPCR fuel system utilizes a radial piston pump that provides high pressure:

Answer 31

Fuel for the injection process

Question 32

In a HPRC fuel injector, what keeps the injector needle valve closed between injections?

Answer 32

A spring and the high pressure fuel on top the intermediate valve

Question 33

What the purpose of using the extremely high pressure that are found in the HPCR system.

Answer 33

Better atomization of the fuel

Question 34

What is the purpose of a pilot injection?

Answer 34

Pilot injection develops a flame front in the cylinder before the main fuel charge is injected which helps reduce overall engine noise and emissions

Question 35

What are the main components of the EUP fuel system(6)?

Answer 35

``` Engine control unit Vehicle control unit Sensors, switches and wiring Fuel transfer system Camshaft actuated electronic pumps Injection lines and nozzles ```

Question 36

To begin injection, the EUP solenoid is energized and this _____ the poppet valve:

Answer 36

Closes

Question 37

What component does the high pressure oil act on inside act on inside the HEUI injector

Answer 37

The intensifier piston assembly

Question 38

T/F In a HPCR system, when the engine is shutdown, there will be no pressure in the common rail and the injection lines?

Answer 38

False. In most systems there will be about 1000 PSI residual pressure

Question 39

T/F In the HPCR fuel system, to begin the injection process, the injector control valve must be opened.

Answer 39

True

Question 40

In a HPCR fuel injector, what keeps the injector needle valve closed between injections?

Answer 40

A spring and the high pressure fuel on top of the intermediate valve

Question 41

What is fuel pressure during HEUI pilot injection?

Answer 41

About 4500 PSI

Question 42

on a system with a multi-plunger injection pump, the fuel injection nozzles atomize and distribute the fuel in the combustion chamber. What type of injection nozzle is this?

Answer 42

hydraulic nozzle

Question 43

What does "TRAMP" mean in a fuel system.

Answer 43

``` T = timing R = rate A = atomization M = metering P = penetration ```

Question 44

electronic unit type injectors are actuated by?

Answer 44

mechanical drive mecanism