IMS Operation and Service of Diesel Engines
48 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is a primary reason diesel engines are more expensive to build than gasoline engines?

  • They require a more rugged design and a precise fuel system. (correct)
  • They use a simpler fuel system.
  • They use a spark to ignite the fuel.
  • They have a lower compression ratio.

What distinguishes diesel engine ignition from gasoline engine ignition?

  • Diesel engines use the heat from compressed air while gasoline engines use a spark. (correct)
  • Diesel engines use a throttle to control air intake, while gasoline engines do not.
  • Diesel engines use a spark plug while gasoline engines use compressed air.
  • Diesel engines use a carburetor while gasoline engines use fuel injectors.

Which component is responsible for increasing the fuel pressure to approximately 2,000 - 5,000 psi?

  • Injector pump (correct)
  • Fuel transfer pump
  • Injector nozzle
  • Fuel filter

What is a characteristic unique to diesel engines regarding air intake?

<p>They operate with an excess of air. (D)</p> Signup and view all the answers

What is the primary function of the fuel filters in a diesel fuel system?

<p>To remove foreign particles and water (A)</p> Signup and view all the answers

Which type of injection pump uses a single set of plungers to supply fuel to all injectors?

<p>Distribution type injector pump (A)</p> Signup and view all the answers

What is the typical range of pressures at which fuel is injected in a diesel engine?

<p>2000 to 5000 psi (A)</p> Signup and view all the answers

What is the approximate low-pressure range of the fuel transfer pump?

<p>4 - 10 psi (A)</p> Signup and view all the answers

Which component of a diesel fuel system stores the fuel on the equipment?

<p>Fuel tank (C)</p> Signup and view all the answers

What is the primary function of fuel lines in a diesel fuel system?

<p>To carry fuel from the tank to the cylinder. (D)</p> Signup and view all the answers

Which component in a diesel fuel system atomizes the fuel before it enters the combustion chamber?

<p>Injector nozzles (A)</p> Signup and view all the answers

According to the provided table, which fuel type has the best fuel economy?

<p>Diesel fuel (A)</p> Signup and view all the answers

In a distributor type injection pump, what mechanism is used to move the plungers to create pressure?

<p>Lobes on a cam ring (C)</p> Signup and view all the answers

Which type of fuel is noted as having the least motor oil contamination?

<p>LP-gas (B)</p> Signup and view all the answers

Which type of injection pump is commonly used on engines of 125 horsepower or greater, due to its ability to delivery larger quantities of fuel?

<p>In-line injection pump (C)</p> Signup and view all the answers

What is the role of the metering valve in a distributor injection pump?

<p>To determine the amount of fuel allowed to enter the pump (D)</p> Signup and view all the answers

What component is utilized in in-line pumps to pressurize fuel?

<p>Plungers in barrels (C)</p> Signup and view all the answers

What feature of the plunger within an in-line pump determines the duration that fuel ports are open or closed?

<p>The spiral groove (helix) (B)</p> Signup and view all the answers

What component in an in-line pump causes the plungers to move inside their barrels?

<p>Camshaft (A)</p> Signup and view all the answers

What component directly controls the position of the plungers helix?

<p>The control rack (C)</p> Signup and view all the answers

What action allows more fuel to be delivered to the injector in an in-line pump?

<p>Turning the plungers so the helix covers the fuel discharge port for the full stroke (A)</p> Signup and view all the answers

Which of the following is NOT a standard test performed on a diesel pump test stand?

<p>Timing test (C)</p> Signup and view all the answers

Which type of fuel line is designed to handle the highest pressures?

<p>Heavy-weight lines (B)</p> Signup and view all the answers

What is a characteristic of heavy-weight fuel lines?

<p>Small inside diameter and thick walls (C)</p> Signup and view all the answers

What is the primary function of fuel leak-off lines in a diesel engine?

<p>To return low-pressure fuel from the injectors and pump to the tank. (A)</p> Signup and view all the answers

What is the recommended method for detecting fuel line leaks?

<p>Use a sheet of paper to check for fuel spray. (A)</p> Signup and view all the answers

When replacing a fuel line, what is the MOST important consideration?

<p>Using a line that is the same size, shape, inside diameter, and length as the original. (D)</p> Signup and view all the answers

What is the primary reason for using a series of filters in a diesel fuel system?

<p>To remove impurities and prevent damage to injection components. (A)</p> Signup and view all the answers

Which of the following is typically the first stage of filtration in a diesel fuel system?

<p>Filter screen at the tank or transfer pump (C)</p> Signup and view all the answers

Which of these filtration methods is a mechanical process that uses a screen to trap particles?

<p>Straining. (C)</p> Signup and view all the answers

What materials are commonly used in filters that work using absorption?

<p>Cotton waste, cellulose, felt, or woven yarn. (D)</p> Signup and view all the answers

What method is typically used for removing water from diesel fuel in a filter?

<p>Magnetic separation (D)</p> Signup and view all the answers

What is the primary function of the chemicals used to treat paper filters in fuel systems?

<p>To cause water to form droplets (C)</p> Signup and view all the answers

How do fuel conditioners added to diesel fuel tanks primarily work?

<p>By causing water to form droplets and settle out (D)</p> Signup and view all the answers

In a fuel system with filters arranged in series, what is a key characteristic?

<p>All fuel must pass through the first filter before moving to the next (D)</p> Signup and view all the answers

What is an advantage of using parallel filters in a fuel system?

<p>A larger volume of fuel can be moved (C)</p> Signup and view all the answers

Failure to maintain fuel filters and water traps can lead to which of the following issues?

<p>Decreased engine power, fuel efficiency, and fuel system damage (A)</p> Signup and view all the answers

Which of the following is NOT considered a basic component of an injector nozzle?

<p>Fuel line (A)</p> Signup and view all the answers

What is 'cracking pressure' in the context of injector nozzles?

<p>The pressure required to open the nozzle valve and allow fuel to spray. (D)</p> Signup and view all the answers

What is a defining characteristic of most modern injector nozzles?

<p>They are closed-type nozzles with pressure acting only on one side of the nozzle valve. (C)</p> Signup and view all the answers

What happens to the nozzle valve in an inward-opening nozzle when cracking pressure is reached?

<p>It retracts into the spray tip. (D)</p> Signup and view all the answers

How does an outward-opening nozzle function when cracking pressure is reached?

<p>It opens outward to deliver the fuel. (B)</p> Signup and view all the answers

What is the typical relationship between cracking pressures of inward and outward opening nozzles?

<p>Outward opening nozzles usually have lower cracking pressure. (A)</p> Signup and view all the answers

What is the consequence of using the wrong type of injector nozzle in an engine?

<p>The engine's power and fuel efficiency may be decreased or the engine may not start. (A)</p> Signup and view all the answers

What should always be consulted before servicing or repairing injector nozzles or the injection system?

<p>The operator's or technical manual. (C)</p> Signup and view all the answers

According to the content, what is the main reason diesel engines may have difficulty starting in cold weather?

<p>The low temperature prevents sufficient fuel vaporization from happening. (A)</p> Signup and view all the answers

What is the common active ingredient found in starting fluids used for diesel engines?

<p>Ether (B)</p> Signup and view all the answers

What is the primary function of glow plugs in diesel engines?

<p>To heat the inside of the combustion chamber to aid in combustion. (D)</p> Signup and view all the answers

Flashcards

Diesel Fuel

A type of fuel used in modern agricultural equipment that is less expensive, has higher power potential, and is safer to handle than gasoline or LP gas.

Fuel Injection

The process of injecting fuel under high pressure into the combustion chamber of a diesel engine.

Diesel Fuel System

The system responsible for delivering fuel at high pressure to the combustion chamber in a diesel engine.

Fuel Tank

The part of the fuel system that stores fuel for the engine.

Signup and view all the flashcards

Fuel Lines

The tubes that carry fuel from the fuel tank to the engine.

Signup and view all the flashcards

Direct Injection System

A type of fuel injection system where fuel is injected directly into the cylinder or combustion chamber.

Signup and view all the flashcards

Fuel Injection Pressure

The pressure at which diesel fuel is injected into the combustion chamber.

Signup and view all the flashcards

High-Pressure Pump

The precision components that regulate and control the fuel delivery in diesel engines.

Signup and view all the flashcards

Fuel transfer pump

A pump that transfers fuel from the tank to the injector pump, operating at low pressure (4-10 psi).

Signup and view all the flashcards

Fuel filters

Components that remove contaminants like particles and water from the fuel before it reaches the injector pump.

Signup and view all the flashcards

Injector pump

A high-pressure pump that meters and delivers fuel to the injectors.

Signup and view all the flashcards

Injector nozzles

Components that atomize and spray fuel into the combustion chamber.

Signup and view all the flashcards

Distribution type injection pump

A type of injector pump that uses a single set of plungers to supply fuel to all injectors.

Signup and view all the flashcards

In-line type injection pump

A type of injector pump with an individual plunger for each cylinder.

Signup and view all the flashcards

Distributor injection pump

A type of injection pump found commonly in agricultural equipment. It uses a single pump and distributor rotor to deliver fuel to injectors.

Signup and view all the flashcards

In-line injection pump

A type of injection pump used in high-horsepower engines. It has a separate plunger for each cylinder, which is housed within one pump body.

Signup and view all the flashcards

In-line pump

A type of fuel pump used in many diesel engines that uses plungers inside barrels to pressurize fuel.

Signup and view all the flashcards

Ports

Openings in the barrel of an in-line pump that allow fuel to enter and be pressurized.

Signup and view all the flashcards

Helix

A spiral groove machined into the side of a plunger in an in-line fuel pump, used to control fuel flow.

Signup and view all the flashcards

Control rack

A component in an in-line fuel pump that controls the position of the helix on the plungers, adjusting fuel delivery.

Signup and view all the flashcards

Heavy-weight fuel lines

Thick-walled fuel lines used to transport high-pressure fuel between the injector pump and injector nozzle.

Signup and view all the flashcards

Medium-weight fuel lines

Fuel lines with thinner walls and larger inside diameter, used in lower pressure parts of the fuel system.

Signup and view all the flashcards

Light-weight fuel lines

Fuel lines with the thinnest walls and largest inside diameter, used for low-pressure fuel transfer.

Signup and view all the flashcards

Injection pump test stand

A specialized piece of equipment used for testing common rail diesel fuel pumps.

Signup and view all the flashcards

Fuel leak-off lines

Fuel lines that carry low-pressure fuel (less than 5 psi) back to the tank from injectors and the injector pump.

Signup and view all the flashcards

Fuel line inspection

Fuel lines should be checked regularly for leaks, breaks, or loose connections.

Signup and view all the flashcards

Fuel line replacement

The service manual provides specific instructions for replacing fuel lines.

Signup and view all the flashcards

Diesel fuel filtration

Diesel fuels tend to have impurities requiring a filtration system to prevent damage to the sensitive injection system.

Signup and view all the flashcards

Diesel fuel filter stages

Diesel fuel systems typically have three stages of filters: a screen at the tank, a primary filter, and a secondary filter, each removing particles of increasing fineness.

Signup and view all the flashcards

Water trap

A trap that collects water and sediment from fuel, which can be drained periodically.

Signup and view all the flashcards

Straining (filtration)

A mechanical filtering method using a screen with holes to trap particles larger than the holes.

Signup and view all the flashcards

Absorption (filtration)

A filtering method using a material that traps particles and absorbs moisture.

Signup and view all the flashcards

Fuel Atomization

The process of breaking down fuel into tiny droplets, creating a fine mist for efficient combustion.

Signup and view all the flashcards

Fuel Water Separator

A filter designed to remove water from fuel by causing it to condense and settle.

Signup and view all the flashcards

Cracking Pressure

The pressure that must be reached before fuel is injected into the combustion chamber.

Signup and view all the flashcards

Series Filtering

A type of fuel filter where fuel passes through all filters in sequence.

Signup and view all the flashcards

Parallel Filtering

A type of fuel filter where fuel is divided and passes through multiple filters simultaneously.

Signup and view all the flashcards

Nozzle Valve

The part of the injector nozzle that controls the flow of fuel.

Signup and view all the flashcards

Spray Tip

The tip of the injector nozzle that shapes the fuel spray pattern.

Signup and view all the flashcards

Inward-Opening Nozzle

A type of injector nozzle where the nozzle valve opens inward.

Signup and view all the flashcards

Outward-opening nozzles

Nozzles that open outward when cracking pressure is reached, delivering fuel.

Signup and view all the flashcards

Glow plug

A specialized electric heater located near the injection nozzle, heating the combustion chamber to aid in cold starts.

Signup and view all the flashcards

Starting fluid (ether)

A volatile liquid used to help start diesel engines in cold weather by igniting easily.

Signup and view all the flashcards

Absorption filtering

A process that removes foreign particles and some moisture from diesel fuel.

Signup and view all the flashcards

Cold weather conditions

The state where the temperature of the engine is too low for combustion to occur.

Signup and view all the flashcards

Combustion

The process of burning fuel vapor inside a diesel engine's combustion chamber, powered by the heat of compressed air.

Signup and view all the flashcards

Study Notes

Diesel Fuel Systems

  • Diesel fuel is preferred for modern agricultural equipment due to its lower cost, higher power potential, lower volatility, and safer handling.
  • Diesel engines differ from gasoline/LPG engines in fuel injection pressure, ignition (heat from compressed air instead of sparks), fuel quality, and throttle control (excess air).
  • Diesel engines can operate on either two-stroke or four-stroke cycles.
  • Fuel injection pressure ranges from 2000-5000 psi, requiring precise fuel systems.
  • Fuel economy: Diesel > LPG > Gasoline
  • Maintenance level: LPG > Diesel > Gasoline
  • Weight per horsepower ratio: Diesel > LPG > Gasoline
  • Cold starting qualities: Gasoline > Diesel > LPG
  • Acceleration rate: Gasoline ≈ LPG > Diesel;

Parts of a Diesel Fuel System

  • Fuel tank: Stores fuel.
  • Fuel lines: Carry fuel from the tank to the cylinders.
  • Fuel transfer pump: Pumps fuel from the tank through filters to the injector pump (low pressure).
  • Fuel filters: Remove impurities (particulates and water) from fuel before it enters the injector pump.
  • Injector pump: High-pressure pump, meters and delivers fuel to injectors.
  • Injector nozzles: Atomize and spray the fuel into the combustion chamber.

Diesel Fuel System Operation

  • Diesel systems operate at two pressure levels: (1) low pressure (4-10 psi) to transfer fuel from the tank to the injector pump, and (2) high pressure (2000-5000 psi) to deliver fuel to the injectors.
  • Two basic types of injector pumps: (1) distribution type - one set of plungers that works together to deliver fuel to all injectors, and (2) in-line type - individual plunger for each injector.

Distributor Injection Pumps

  • Use one pump to deliver fuel to injectors.
  • Rotary pump design with cylinder bores and plungers moved by lobes on a cam ring.
  • Rotor rotates inside a hydraulic head to line up discharge passages with injector ports.
  • Metering valve controls fuel amount delivered.
  • Some may have automatic speed/load advance systems.

In-Line Injection Pumps

  • One plunger per cylinder housed in one common housing.
  • Suitable for larger engines (>125 horsepower).
  • Plungers within barrels to pressurize the fuel.
  • Camshaft moves plungers to deliver fuel.
  • Spiral grooves (helix) on plungers control fuel delivery timing.

Fuel Lines

  • Heavy-weight lines: High pressure (up to 5,000 psi).
  • Medium-weight lines: Moderate pressure (5-45 psi).
  • Light-weight lines: Low pressure (<5 psi).

Fuel Filters

  • Filtering system important to avoid damaging the injection system.
  • Typically has three stages: (1) filter screen, (2) primary filter, (3) secondary filter.
  • Water traps are often included to remove water.

Injector Nozzles

  • Atomize and spray fuel into combustion chambers.
  • Components: Body, Nozzle valve, Spray tip, and Pressure spring.
  • Fuel pressure opens the nozzle valve and sprays fuel.
  • Nozzle size, number and angle of the holes control spray pattern.
  • Two types: (1) Inward-opening, (2) Outward-opening

Starting Diesel Engines

  • Diesel engines utilize compressed air to ignite the fuel.
  • Starting fluids (ether) or glow plugs may be necessary in cold weather to heat the combustion chamber and facilitate easier starting.
  • Consult equipment manuals for recommended starting procedures.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Agricultural Mechanics 8208-B Diesel Fuel Systems PDF

Description

Test your knowledge on the fundamental components and workings of diesel engines. This quiz covers aspects such as ignition, fuel systems, and the differences between diesel and gasoline engines. Dive into the mechanics that make diesel engines unique and efficient.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser