31S07T0 engine peformance theory and operation 2003

ENGINE PERFORMANCE CURRICULUM GOALSThe goal of the Engine Performance Curriculum is to provide you with necessary training to “Fix it right the firsttime.” This Engine Performance Theory

Ford Customer Service Division

Technical Training

Appropriate service methods and proper repair procedures are essential for the safe, reliable operation of all motor vehicles,

as well as the personal safety of the individual doing the work This manual provides general directions for accomplishing service and repair work with tested, effective techniques Following them will help assure reliability.

There are numerous variations in procedures, techniques, tools and parts for servicing vehicles, as well as in the skill of the individual doing the work This manual cannot possibly anticipate all such variations and provide advice or cautions as to each Accordingly, anyone who departs from instructions provided in this manual must first establish that he compromises neither his personal safety nor the vehicle integrity by his choice of methods, tools or parts.

As you read through the procedures, you will come across NOTES, CAUTIONS, and WARNINGS Each one is there for a specific purpose NOTES give you added information that will help you to complete a particular procedure CAUTIONS are given to prevent you from making an error that could damage the vehicle WARNINGS remind you to be especially careful

in those areas where carelessness can cause personal injury The following list contains some general WARNINGS that you should follow when you work on a vehicle.

• Always wear safety glasses for eye protection.

• Use safety stands whenever a procedure requires you to

be under the vehicle.

• Be sure that the ignition switch is always in the OFF

position, unless otherwise required by the procedure.

• Set the parking brake when working on the vehicle If you

have an automatic transmission, set it in PARK unless

instructed otherwise for a specific service operation If

you have a manual transmission it should be in

RE-VERSE (engine OFF) or NEUTRAL (engine ON) unless

instructed otherwise for a specific service operation.

• Operate the engine only in a well-ventilated area to avoid

the danger of carbon monoxide.

• Keep yourself and your clothing away from moving parts

when the engine is running, especially the fan and belts.

• To prevent serious burns, avoid contact with hot metal parts such as the radiator, exhaust manifold, tail pipe, catalytic converter and muffler.

• Do not smoke while working on the vehicle.

• To avoid injury, always remove rings, watches, loose hanging jewelry, and loose clothing before beginning to work on a vehicle Tie long hair securely behind your head.

• Keep hands and other objects clear of the radiator fan blades Electric cooling fans can start to operate at any time by an increase in underhood temperatures, even though the ignition is in the OFF position Therefore, care should be taken to ensure that the electric cooling fan is completely disconnected when working under the hood.

The recommendations and suggestions contained in this manual are made to assist the dealer in improving his dealership parts and/or service department operations These recommendations and suggestions do not supersede or override the provisions of the Warranty and Policy Manual, and in any cases where there may be a conflict, the provisions of the Warranty and Policy Manual shall govern.

The descriptions, testing procedures, and specifications in this handbook were in effect at the time the handbook was approved for printing Ford Motor Company reserves the right to discontinue models at any time, or change specifications, design, or testing procedures without notice and without incurring obligation Any reference to brand names in this manual

is intended merely as an example of the types of tools, lubricants, materials, etc recommended for use Equivalents, if available, may be used The right is reserved to make changes at any time without notice.

WARNING: MANY BRAKE LININGS CONTAIN ASBESTOS FIBERS WHEN WORKING ON BRAKE COMPONENTS, AVOID BREATHING THE DUST BREATHING THE ASBESTOS DUST CAN CAUSE ASBESTOSIS AND CANCER.

Breathing asbestos dust is harmful to your health.

Dust and dirt present on car wheel brake and clutch assemblies may contain asbestos fibers that are hazardous to your health when made airborne by cleaning with compressed air or by dry brushing.

Wheel brake assemblies and clutch facings should be cleaned using a vacuum cleaner recommended for use with asbestos fibers Dust and dirt should be disposed of in a manner that prevents dust exposure, such as sealed bags The bag must be labeled per OSHA instructions and the trash hauler notified as to the contents of the bag.

If a vacuum bag suitable for asbestos is not available, cleaning should be done wet If dust generation is still possible, technicians should wear government approved toxic dust purifying respirators.

OSHA requires areas where asbestos dust generation is possible to be isolated and posted with warning signs Only technicians concerned with performing brake or clutch service should be present in the area.

Copyright © 2003 Ford Motor Company Produced and Coordinated by

Technical Support Operations Ford Customer Service Division

5. Provide me with a clear and thorough explanation of the service performed.

6. Call me within a reasonable amount of time after my service visit to ensure that I'm completely satisfied.

7. Be responsive to questions or concerns

I bring to your attention.

1. Make it convenient to have my

vehicle serviced at your dealership.

2. The Service Advisor should

demonstrate a genuine concern for

my service needs.

3. Fix it right the first time.

4. Complete servicing my vehicle in a

timely and professional manner.

Expectation 3

“Fix It Right The First Time, on Time.”

Both service advisors and technicians are important players when it comes to Expectation

It is our goal to help the technician acquire all of the skills and knowledge necessary to

“Fix It Right The First Time, on Time.” We refer to this as “competency.”

Technician’s Role

Acquire the skills and knowledge for competency in your specialty via:

Engine Performance Curriculum Goals Intro-1 Organization of the Student Information Book Intro-3 Day One Agenda Intro-6 Day Two Agenda Intro-9

IGNITION REVIEW

Student’s Objective 1-1 Content 1-1 Basic Ignition System Operation 1-2 Voltage and Coils 1-3 Ignition Timing 1-13 Ignition Requirements and Operating Conditions 1-17 Distributorless Ignition Systems 1-23 Coil-On-Plug Ignition System 1-41

FUEL/AIR INLET REVIEW

Student’s Objective 2-1 Content 2-1 Fuel and Air Inlet Systems 2-2 Air Intake System 2-9 Air Measurement Systems 2-23 Fuel System 2-27 Fuel Control 2-41

EXHAUST/EMISSION REVIEW

Student’s Objective 3-1 Content 3-1 Exhaust/Emission System 3-2 Positive Crankcase Ventilation (PCV) 3-5 Evaporative Emission (EVAP) System 3-13 Exhaust Gas Recirculation (EGR) 3-27 Secondary Air Injection Reaction (AIR) 3-39 Catalytic Converter (CAT) 3-45 OBDII 3-53

WORKSHEETS

DAY ONE

Worksheet 1 Secondary Concern Worksheets-1A Worksheet 2 Cop Coil Concern Worksheets-2A Worksheet 3 Air Leak Worksheets-3A Worksheet 4 Injector Concern Worksheets-4A

DAY TWO

Worksheet 1 Fuel Pressure Worksheets-1A Worksheet 2 Drive Session Worksheets-2A Worksheet 3 Vacuum Leak Worksheets-3A Worksheet 4 Electronic Publications Navigation Worksheets-4A

NOTES

ENGINE PERFORMANCE CURRICULUM GOALS

The goal of the Engine Performance Curriculum is to provide you with necessary training to “Fix it right the firsttime.” This Engine Performance Theory and Operation classroom course provides you with hands-on practice as

it relates to the theory and operation, as well as, the relationships among engine performance systems and systemtypes

Planned Training Pathway

Ford Motor Company has identified the skills and knowledge necessary to meet the Engine Performance

Curriculum goals The Planned Training Pathway is a sequence of courses that are designed to provide you withthese skills and knowledge

Engine Performance Curriculum Overview

The Engine Performance Curriculum consists of all of the following types of courses:

Web-based – These courses are self-paced The technician is responsible for learning the material on his/her owntime The courses are posted on the Internet and technicians are given the appropriate access codes

Ford Multimedia Training (FMT) – These courses are also self-paced The multimedia courses are highly

interactive and allow the technician to simulate hands-on activities

Classroom – The classroom courses allow for application of the skills and knowledge learned in the prerequisitecourses through hands-on, real-world scenarios

FORDSTAR – These courses are instructor-led, interactive, live broadcasts presented over the FORDSTARDistance Learning Network The instructor presents information, asks questions, and interacts with the

technicians Demonstrations and video clips are used to present material

How to Complete the Curriculum

To successfully complete the Engine Performance Curriculum, you must take the following sequence of courses:

Ignition System Theory and Operation –

ORGANIZATION OF THE STUDENT INFORMATION BOOK

The student information book is divided into three sections that include the following information:

– Each Lesson starts with the Student Objectives and a content outline

– Workbook pages contain graphics and review material from previous WBT courses

l Day One and Day Two Worksheets

– Contains student worksheets and review questions

Target Audience

The Engine Performance Theory and Operation classroom is designed for entry-level Ford Motor Company

engine performance technicians

Course Length

This is a two-day course

Course Prerequisites

Before you enroll in this course, you must meet the following prerequisites:

l Basic Electrical Part 3 – 34S03T0 (Classroom)

l Electronics Part 3 – 34S06T0 (Classroom)

l WBT Courses:

– Air, Fuel, Ignition, and Exhaust Systems Relationships – 31S04W0

– OBDII Monitors – 31S05W0

Course Description

This is a two-day hands-on course designed to provide you with maximum hands-on application of EnginePerformance systems theory and operation as well as the relationships between systems and system types duringnormal operating conditions The first day is a combination of instructor review and lecture, instructor-led

demonstrations, and hands-on workstations The second day is a continuation of the hands-on workstations andculminates in the final exam

Course Objectives

Upon completion of the Engine Performance Theory and Operation classroom, you will be able to:

l Review Critical Concepts from the prerequisite WBT courses

– Explain the critical concepts of Ignition Systems theory and operations

– Explain the critical concepts of Fuel and Air Inlet System theory operations

– Explain the critical concepts of Exhaust/Emissions Systems theory operations

– Explain the relationships between the Air, Fuel, Ignition, and Exhaust/Emissions systems

– Explain the purpose and function of the OBD II monitors

l Locate appropriate information in the Ford Electronic Publications System

l Perform and interpret measurement results using specific diagnostic tools

– Perform and interpret measurement results for normal systems operations

– Perform measurements on system operations under certain conditions

– Select PIDs

– Monitor systems operations using PID values

– Perform Spark Duration and Peak kV tests

– Explain the effect of certain conditions on systems operations

– Explain how the systems compensate for certain conditions

Course Structure

The Engine Performance Theory and Operation classroom course has the following structure:

l Review – You will be asked to complete review questions that address content covered in the prerequisitecourses Afterwards, the instructor will direct a review/lecture that includes critical concepts necessary forunderstanding the theory and operation of engine performance systems The review questions and individualstudent responses to these questions can be used as a guide to conduct this lecture In this way, the instructorcan also address any “often-missed” review questions

l Instructor Demonstration – The instructor will demonstrate WDS as it pertains to the workstations

l Workstations – The instructor will present the concepts that are critical to successfully completing the

workstations You will participate in two on-vehicle workstations, and two electronic resource activities eachday

l Worksheets – All workstations have an accompanying worksheet designed to complement the hands-on

activities All workstations and worksheets are identified by number

l Evaluation – At the end of the two-day course, the instructor will ask you to complete a final written test,which includes a WDS recorded session where you are asked to evaluate data, and a course evaluation

You may use all of the reference material available to you in the classroom, including workshop manuals and thestudent information book However, the sharing of answers with the other technicians will not be permitted

DAY ONE AGENDA

The agenda for Day One is as follows:

START FINISH

Review of critical concepts as determined by results of review questions 9:45 a.m 11:45 a.m

Workstation #1 – Worksheet 1 – Secondary Ignition (on-vehicle) 1:30 p.m 2:00 p.m

Workstation #2 – Worksheet 2 – COP Fault (recorded WDS session) 2:00 p.m 2:30 p.m

Workstation #3 – Worksheet 3 – Air Leak (on-vehicle) 2:45 p.m 3:15 p.m

Workstation #4 – Worksheet 4 – Injector Fault (recorded WDS session) 3:15 p.m 3:45 p.m.Review four (4) worksheets from Day One rotation 3:45 p.m 4:45 p.m

Day One Flowchart

Welcome and Course Overview

Review Questions

Debrief of Day One Workstation Rotations

Day One – Afternoon Workstation Rotations

Team 1 –

Worksheet 3 Air Leak On-Vehicle

Team 1 –

Worksheet 4 Injector Fault Recorded WDS Session

Team 2 –

Worksheet 4 Injector Fault Recorded WDS Session

Team 2 –

Worksheet 1 Secondary Ignition On-Vehicle

Team 3 –

Worksheet 1 Secondary Ignition On-Vehicle

Team 3 –

Worksheet 2 COP Fault Recorded WDS Session

Team 4 –

Worksheet 2 COP Fault Recorded WDS Session

Team 4 –

Worksheet 3 Air Leak On-Vehicle

DAY TWO AGENDA

The agenda for Day Two is as follows:

START FINISH

Workstation #1 – Worksheet 1 – Fuel Pressure (on-vehicle) 9:00 a.m 9:30 a.m

Workstation #2 – Worksheet 2 – Drive Recording (recorded WDS session) 9:30 a.m 10:00 a.m

Workstation #3 – Worksheet 3 – Vacuum Leak (on-vehicle) 10:15 a.m 10:45 a.m

Workstation #4 – Worksheet 4 – Electronic Publications Navigation (PC) 10:45 a.m 11:15 a.m.Review four (4) worksheets from Day Two rotation 11:15 a.m 12:15 p.m

Description of

Day Two Workstations

Lunch

End

Break

Day Two Workstation Rotations

Post-Test

Debrief of Day Two Workstation RotationsDay Two Flowchart

Recording WDS Session

Team 1 – Worksheet 3 Vacuum Leak On-Vehicle

Team 1 – Worksheet 4 Elect Pubs.

Navigation (PC)

Team 2 – Worksheet 4 Elect Pubs.

Navigation (PC)

Team 2 – Worksheet 1 Fuel

Pressure On-Vehicle

Navigation (PC)

Team 3 – Worksheet 1 Fuel

Pressure On-Vehicle

Team 3 – Worksheet 2 Drive

Recording WDS Session

Pressure On-Vehicle

Team 4 – Worksheet 2 Drive

Recording WDS Session

Team 4 – Worksheet 3 Vacuum Leak On-VehicleDay Two – Morning Workstation Rotations

NOTES

STUDENT’S OBJECTIVE

l Review the critical concepts of the ignition system

theory and operation

CONTENT

l Basic Ignition System Operation

l Voltage and Coils

l Ignition Timing

l Ignition Requirements and Operating Conditions

l Distributorless Ignition Systems

l Coil-On-Plug Ignition Systems

BASIC IGNITION SYSTEM OPERATION

Basic Ignition System

The purpose of the ignition system is to provide a spark to the correct cylinder at the correct time to ignite the air/fuel mixture The cylinders must fire in the proper order and at the precise time, depending on engine speed andload Proper ignition is critical to engine performance, fuel economy, and exhaust emissions Improper ignitioncan cause driveability symptoms and create excessive emissions

All ignition systems operate in a similar manner Current flow in the coil primary circuit is interrupted to produce

a high voltage in the secondary coil circuit, which fires the spark plug The differences are in how the ignition

VOLTAGE AND COILS

All ignition coils have a primary and secondary winding The secondary winding contains many times morewindings than the primary winding

EP1002 -A/VF

3

2 1 kV

Ignition Primary Circuit

The ignition primary circuit is the low voltage portion of the ignition system The function of the primary circuit

is to energize the ignition coil in order to produce the high voltage required in the secondary circuit The primarycircuit consists of the supply voltage circuit and the ground (coil -) circuit

Supply Voltage Circuit

Supply Voltage Circuit

When the ignition switch is in the ON position, battery voltage is applied to the primary winding of the ignitioncoil

Before the introduction of electronic ignition systems, the ground circuit for the coil primary winding was

provided and interrupted by a set of breaker points

Primary Current Flow

When the maximum primary current flow is obtained (coil saturation), the magnetic field is at maximum

strength It takes approximately 1.5 to 4.0 milliseconds (ms), depending on coil type, for most coils to reachtarget current

Magnetic Field Collapse/Induction

Magnetic Field Collapse/Induction

Secondary Circuit Voltage and Ignition

Quality Spark

Most automobile electrical systems operate with 12-14 volts To produce a sufficient spark with proper duration,

a high voltage electric charge is required to jump across the spark plug’s air gap Thousands of volts are required

to produce a quality spark The ignition system is responsible for transforming this battery/charging systemvoltage into the required high voltage

EP1007-A/VF

is referred to as “weak spark.”

EP1008-A/VF

Spark and Ignition

Flame Propagation

To ignite an air/fuel mixture, the spark must get some fuel molecules hot enough to burn When these fuel

molecules burn, they give off enough heat to ignite other fuel molecules

Under ideal conditions, this process will continue until all of the fuel molecules in the combustion chamber areburned This process is referred to as flame propagation

A weak spark will not produce enough heat to ignite air/fuel molecules reliably The spark may only ignite an air/fuel mixture some of the time or not at all, depending on the intensity of the spark

EP1009-A/VF

Lean mixtures are difficult to ignite because fuel molecules are far apart Rich mixtures are easier to ignitebecause the fuel molecules are closer together.

NOTES

IGNITION TIMING

Base Timing

Ignition timing, also called spark timing, refers to how early or how late the spark plugs fire in relation to theposition of the piston on the compression stroke For the engine to run efficiently and produce low emissions, thecombustion process should be completed in a predetermined time frame

Base timing is determined on an engine dynamometer Ignition timing is adjusted to produce the maximumamount of torque at various rpm and load points This timing is called Minimum Spark Advance for best Torque(MBT) These timing values are stored in the PCM in an rpm/load table

EP1011-A/VF

10 33 23

Spark Advance and Engine Speed

The PCM calculates spark advance based primarily on rpm and load in an effort to achieve the best engine

performance for current operating conditions

l Spark is advanced for the following conditions:

– Rich air/fuel mixture

2

l Spark is retarded for the following conditions:

– Lean air/fuel mixture

– Low rpm operation

– Heavy load

– High compression pressures

– High intake air temperatures

– High engine coolant temperatures

3 1

4

NOTES

IGNITION REQUIREMENTS AND OPERATING CONDITIONS

Secondary Ignition Requirements

Item Description

1 Cranking

2 Idle

Since the engine operates under various conditions, the ignition system must also operate under these conditions

To properly evaluate and diagnose the ignition system, it is necessary to identify ignition requirements for eachengine condition and operating mode

Operating Conditions

Compression pressures and air/fuel ratios affect ignition secondary voltage and duration requirements When theair/fuel mixture is compressed, higher secondary voltage is required to arc the spark plug’s gap This is becausethere is more resistance to overcome

There are many more air molecules than fuel molecules in a typical air/fuel mixture Compressed air moleculesadd resistance that must be overcome by higher ignition voltage Compression pressures and air/fuel ratioschange with different operating conditions

kV 20

Secondary Voltage During Cranking

Engine cranking speed for most engines is between 110 – 250 rpm Slower engine speeds cause lower

compression pressures Therefore, the secondary voltage requirements for ignition during cranking are typicallylower than for other operating modes In addition, richer air/fuel mixtures are used during cranking, which

reduces secondary voltage requirements Under certain conditions, such as the first few sparks (until the air/fuelmixture is drawn into the engine), secondary voltage during cranking can exceed steady state idle voltage

Ignition timing also has an effect on secondary voltage requirements Compression pressures increase as thepiston moves toward Top Dead Center (TDC), requiring higher secondary voltages During cranking, ignitiontiming is typically near TDC This would normally increase the secondary voltage requirement, but since

cranking speed is not capable of producing maximum compression pressures, secondary voltage is usually normal

to low, depending on the condition of the engine

EP1015-A/VF

kV 5

0

Secondary Voltage During Idle

During idle, ignition timing is typically 10° Before Top Dead Center (BTDC) or greater However, compressionpressures are higher at idle than during cranking because of increased engine speed In addition, the air/fuelmixtures become leaner once the engine is running, and leaner air/fuel mixtures require higher voltage

EP1016-A/VF

5

0

10 15 kV 20

Secondary Voltage During Acceleration

During acceleration, compression pressures in the cylinder are very high The ignition secondary voltage

increases to overcome high resistance caused by high compression pressures

EP1018-A/VF

30 kV

20 10 0

NOTES