190203c Basic Mechanical Fuel Injection Systems

Question 0

What is injection timing?

Answer 0

Injecting the fuel at the correct time

several degrees BTDC.

Question 1

All diesel fuel injection systems must perform what three functions

Answer 1

The inject proper amount of fuel at correct time and rate, they atomize the fuel, they inject the fuel at pressure high enough to penetrate the combustion chamber

Question 2

Two types of basic fuel injection?

Answer 2

Multi plunger injection and unit injection

Question 3

Rate of injection can be explained as

Answer 3

Time it takes to inject fuel into the cylinder

Question 4

A controlled injection rate is important because?

Answer 4

It alows for even pressure rise and for proper combustion.

Question 5

If fuel pressure rises to high to quickly what noise will you hear

Answer 5

You should hear a combustion knock

Question 6

BOI refers to

Answer 6

Beginning of injection

Question 7

True or false

if fuel is injected to late. And maximum combustion pressure develops after optimum crank angle power is gained.

Answer 7

False power is lost.

fuel must be inject at the correct time for max hp and least amount of east emissons.

Question 8

True or false. Rate of injection is adjustable by a technician

Answer 8

False. Rate of injection is controlled by fuel injection system design

Question 9

What are the two methods of varying fuel injection timing advance used on diesel engines that must respond to continual changes in speed

Answer 9

Mechanical or electronic

Question 10

What are the two ways to duration can be expressed

Answer 10

Degrees of crankshaft rotation, time for example 1/1000 of a second

Question 11

What two factors control Atomization of fuel

Answer 11

Injection pressure ( set by fuel injection system design) and fuel injection nozzle design (number and size of nozzle spray holes)

Question 12

All fuel injection systems must supply exactly the right quantity of fuel for all engine speed and loads. This is referred to as

Answer 12

Metering

Question 13

What’s the definition of penetration

Answer 13

Penetration is the ability of the fuel spray to reach all areas of the combustion chamber

Question 14

Timing of injections must be how accurate to ensure engine produces maximum power, maximum fuel economy and minimum exhaust emissions?

Answer 14

Timing of injections must be accurate within + or -1° of crankshaft rotation

Question 15

What is metering?

Answer 15

Supply of the correct amount of fuel for all vehicle speeds and loads.

Question 16

How accurate must the metering of fuel be?

Answer 16

The metering must be within 5%

Question 17

Timing of the injections must be accurate to within how many degrees of crankshaft rotation?

Answer 17

+/- 1 degree of crank rotation.

Question 18

Name the two basic types of fuel injection systems.

Answer 18

1. Multi-plunger injection pumps

2. Unit injection system

Question 19

Basic fuel injection systems consist of what 2 sections?

Answer 19

Fuel supply (low psi) and the injection (high psi)

Question 20

Explain how the fuel supply section prepares the fuel for the high pressure section.

Answer 20

It cleans the fuel of contaminants such as dirt and water, removes air trapped in the system and also regulates temperature.

Question 21

True or false, Water separators are combined with primary fuel filters

Answer 21

True, Water separators are often combined with primary fuel filter or installed up stream as a separate unit.

Question 22

What is the function of a transfer pump ?

Answer 22

Move fuel from the tank to the injection pump or unit injection pump.

Question 23

Multi-plunger injection pump would supply what kind of fuel injectors with high pressure fuel

Answer 23

Hydraulic Injection Nozzles

Question 24

The transfer pump for a unit injection system is a separate component driven by what?

Answer 24

engine camshaft or gear train

Question 25

TQ The pumping units are connected to the injection nozzles with high-pressure lines. What are this high pressure lines made out of ?

Answer 25

They are made of equal length heavy wall seamless steel tubing

Question 26

What is the purpose of the fuel transfer pump?

Answer 26

to move fuel from the tank to the fuel injection pump or unit injectors