Motor Vehicle Unit 172 Flashcards
47 Questions
100 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

Injectors in a multi-point injection system usually spray atomized fuel very close to the:

inlet valve

When fitting a knock sensor it should always be:

set to the specific torque setting

A manifold absolute pressure (MAP) sensor measures:

induction air vacuum

The name of the component which rotates in a distributor cap is:

<p>rotor arm</p> Signup and view all the answers

One benefit of using a coil per plug system is that the:

<p>system does not need high tension leads</p> Signup and view all the answers

What three harmful gases will the catalyst convert?

<p>HC, CO, NOx</p> Signup and view all the answers

After a faulty fuel injection air mass meter has been replaced it is often necessary to:

<p>erase existing fault codes</p> Signup and view all the answers

What equipment would be used to check the operational efficiency of replaced MPI fuel injectors?

<p>emissions tester</p> Signup and view all the answers

When checking petrol Multi Point Injection system pressure, the test should be carried out on the:

<p>fuel injector rail</p> Signup and view all the answers

Tuned lengths of both inlet and exhaust manifolds are used to greatly improve:

<p>cylinder filling</p> Signup and view all the answers

When injectors operate individually, this is called:

<p>sequential</p> Signup and view all the answers

A faulty oxygen sensor will affect the:

<p>air/fuel ratio</p> Signup and view all the answers

What effect would an open circuit coolant temperature sensor have on an engine management system?

<p>incorrect engine fuel mixture</p> Signup and view all the answers

In which one of the following components would the ignition pulse generator be located?

<p>electronic control unit</p> Signup and view all the answers

Which one of the following cylinder heads is more likely to cross thread a spark plug?

<p>four cylinder aluminium alloy</p> Signup and view all the answers

If a car fails to crank when starting, which one of the following would normally be the first to be tested?

<p>battery condition</p> Signup and view all the answers

An accurate method of checking ignition timing on an engine with a coil per plug system is to fit a:

<p>hand held ECU interface scanner</p> Signup and view all the answers

Glowing red hot spark plugs often cause an engine running fault called:

<p>pre-ignition</p> Signup and view all the answers

The term pinking refers to a noise heard in the engine when it suffers from being:

<p>advanced</p> Signup and view all the answers

A common cause of poor starting in damp conditions is:

<p>high voltage loss due to tracking</p> Signup and view all the answers

Replaced exhaust components must comply with:

<p>legal noise requirements</p> Signup and view all the answers

Which one of the following items of equipment would be used to check the operational efficiency of a replaced catalyst converter?

<p>exhaust gas analyser</p> Signup and view all the answers

One method of reducing exhaust noise is to use:

<p>baffles plates</p> Signup and view all the answers

A resonator box is fitted to an exhaust system to:

<p>reduce sound levels</p> Signup and view all the answers

Which one of the following can cause internal corrosion of an exhaust system?

<p>by-products of combustion</p> Signup and view all the answers

When removing and replacing light vehicle diesel injectors, which other components should always be replaced?

<p>injector sealing washers</p> Signup and view all the answers

Name one design difference between the SPI and MPI fuel systems:

<p>throttle valve location</p> Signup and view all the answers

Where is a common place on a four-stroke petrol engine for the ignition crank angle sensor to be located?

<p>flywheel</p> Signup and view all the answers

One purpose of a resilient mounting on an exhaust system is to:

<p>permit a degree of system flexibility</p> Signup and view all the answers

What is the purpose of an air filter?

<p>reduces induction noise and premature engine wear</p> Signup and view all the answers

An EOBD system warns of an Electronic Fuel Injection running fault by:

<p>illuminating a warning light</p> Signup and view all the answers

Which one of the following engine running test methods would determine whether a light vehicle electronically controlled diesel injector was working?

<p>connect the vehicle to an EOBD diagnostic machine</p> Signup and view all the answers

When retrieving fault codes, what equipment should initially be connected to the OBD socket?

<p>scanner</p> Signup and view all the answers

A coolant temperature sensor with a Negative Temperature Coefficient (NTC) will:

<p>decrease its resistance as temperature rises</p> Signup and view all the answers

When the petrol fuel to air ratio control is monitored by exhaust Lambda sensors, it is known as:

<p>closed loop</p> Signup and view all the answers

Which one of the following is an important action before removing a spark plug?

<p>removing dust and debris</p> Signup and view all the answers

When examining spark plugs, a white speckled insulator tip would indicate a very:

<p>hot running plug</p> Signup and view all the answers

A simple test for the correct running of an engine is to look at the:

<p>spark plug condition</p> Signup and view all the answers

Which one of the following sensors sends signals to the engine management system for ignition timing adjustments?

<p>knock sensor</p> Signup and view all the answers

Which engine stroke does the spark plug normally fire on?

<p>compression</p> Signup and view all the answers

What would a black soot covered spark plug indicate?

<p>rich mixture</p> Signup and view all the answers

Before replacing an exhaust manifold it must be ensured that:

<p>all mating surfaces are clean and all gaskets are changed</p> Signup and view all the answers

Which one of the following light vehicle exhaust components would normally be fitted to a diesel engine but not fitted to a petrol engine?

<p>particulate filter</p> Signup and view all the answers

Fuel and air swirl in a combustion chamber is assisted by:

<p>cylinder head design</p> Signup and view all the answers

Which one of the following is a symptom of a blocked exhaust?

<p>total lack of power</p> Signup and view all the answers

For what reason do turbocharger bearings require constant cooling?

<p>the turbo is close to the exhaust manifold</p> Signup and view all the answers

Which component distributes high voltage to the distributor cap segments?

<p>rotor arm</p> Signup and view all the answers

Study Notes

Fuel Injection Systems

  • Multi-point injection systems use injectors that spray atomised fuel close to the inlet valve.
  • Sequential operation of injectors allows for improved fuel efficiency by activating each injector individually.

Sensors and Monitoring

  • A manifold absolute pressure (MAP) sensor measures induction air vacuum, essential for fuel management.
  • Knock sensors must be set to specific torque settings during installation to ensure proper operation.
  • Oxygen sensors impact the air/fuel ratio and must be functional for optimal engine management.
  • Coolant temperature sensors with a Negative Temperature Coefficient (NTC) decrease resistance as the temperature rises, aiding in accurate engine control.

Emissions Control

  • Catalysts convert harmful gases: hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx).
  • Emissions testers are used to check the operational efficiency of replaced multi-point fuel injectors.
  • Exhaust gas analysers assess catalyst converter efficiency.

Ignition System

  • The rotor arm rotates within the distributor cap to distribute high voltage.
  • Spark plugs should be examined for condition; white speckled insulator indicates overheating, while black soot suggests a rich fuel mixture.
  • Ignition timing can be checked accurately using a hand-held ECU interface scanner.

Exhaust System

  • Exhaust components must meet legal noise requirements after replacement.
  • Resonator boxes and baffle plates help reduce sound levels in the exhaust system.
  • Internal corrosion of exhaust systems can be caused by combustion by-products.

Maintenance Practices

  • Replace injector sealing washers when changing diesel injectors to prevent leaks.
  • Clean all mating surfaces and replace gaskets before installing a new exhaust manifold.
  • Dust and debris should be removed before spark plug replacement to avoid contamination.

Engine Performance and Diagnostics

  • A faulty fuel injection air mass meter requires erasing fault codes after replacement to reset the system.
  • EOBD systems alert drivers to Electronic Fuel Injection issues by illuminating warning lights.
  • Turbocharger bearings require constant cooling due to their proximity to the exhaust manifold.

Miscellaneous

  • A particulate filter is typically found in diesel engines but not in petrol engines.
  • Cylinder head design facilitates fuel and air swirl in the combustion chamber, enhancing combustion efficiency.
  • Symptoms of a blocked exhaust include a total lack of engine power.

Studying That Suits You

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

Quiz Team

Description

Test your knowledge with these flashcards from Motor Vehicle Unit 172. Each card contains essential definitions and terms related to automotive technology and systems. Perfect for students looking to reinforce their understanding of multi-point injection systems, sensors, and more.

More Like This

Use Quizgecko on...
Browser
Browser