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student guide

1999-2002

Ford Bi-FuelVehicles

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IMPORTANT SAFETY NOTICE

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 these

directions 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/she compromises neither his/her personal safety nor the vehicle integrity by his/her

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 NEUTRAL (engine OFF) or NEUTRAL (engine ON) WITH

THE PARKING BRAKE ON unless instructed otherwise for a specific 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, such as the fan and belts, when the engine is running.

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

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In any cases where there may be a conflict, the provisions of the Warranty and Policy Manual or the

Workshop 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.

Produced and Coordinated by Technical Support Operations, Ford Customer Service Division

March, 2002

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CONTENTS

INTRODUCTION AND PREREQUISITE REVIEW

ALTERNATIVE FUEL VEHICLE (AFV) CURRICULUM............................................................................. Intro-2SERVICE STANDARDS ........................................................................................................................... Intro-5

PREREQUISITE REVIEW ........................................................................................................................ Intro-6

LESSON 1: INTRODUCTION TO BI-FUEL VEHICLES

INTRODUCTION TO BI-FUEL VEHICLES ...................................................................................................1 - 2Advantages of Bi-Fuel Vehicles ....................................................................................................................1 - 3

Alternative Fuel Comparison Table ...............................................................................................................1 - 4Identification of Ford Bi-Fuel Vehicles ...........................................................................................................1 - 5

Changes to Base Vehicle Components on LPG/CNG Bi-Fuel Vehicles .........................................................1 - 6Changes to Base Vehicle Operating Strategies ............................................................................................1 - 7Supplemental Information On Alternative Fuel Vehicles ................................................................................1 - 8

LESSON 2A: INTRODUCTION TO LPG BI-FUEL VEHICLES

BI-FUEL LPG FUEL SYSTEM THEORY OF OPERATION ........................................................................ 2A - 2

ACTIVITY 2A - WORKSHEET A (Hands-On) ............................................................................................ 2A - 8

ACTIVITY 2A - WORKSHEET B (Written) ................................................................................................. 2A - 9ACTIVITY 2A - LPG SAFETY QUIZ (Written) .......................................................................................... 2A - 11

LESSON 2B: INTRODUCTION TO CNG BI-FUEL VEHICLES

BI-FUEL CNG FUEL SYSTEM THEORY OF OPERATION ....................................................................... 2B - 2

CNG FUEL SYSTEM PRESSURES .......................................................................................................... 2B - 5

ACTIVITY 2B - WORKSHEET C (Hands-On) ............................................................................................ 2B - 8

ACTIVITY 2B - WORKSHEET D (Written) ................................................................................................. 2B - 9ACTIVITY 2B - CNG SAFETY QUIZ (Written) ......................................................................................... 2B - 11

LESSON 3A: LPG FUEL SYSTEM COMPONENTS

LPG FUEL SYSTEM COMPONENTS ........................................................................................................ 3A -2LPG Fuel Fill Valve ..................................................................................................................................... 3A -3

LPG Fuel Tanks .......................................................................................................................................... 3A -4

Fuel Tank Testing and Inspection ................................................................................................................ 3A -7LPG Fuel Level Float .................................................................................................................................. 3A -8Fuel Lines ................................................................................................................................................... 3A -9Vaporizer .................................................................................................................................................. 3A -10

Electric Fuel Lockoff Solenoid ................................................................................................................... 3A -12Compuvalve (Fuel Metering Operation) .................................................................................................... 3A -13

Fuel Rails and Injector Sleeves................................................................................................................. 3A -16

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CONTENTS

ACTIVITY 3A - WORKSHEET E (Hands-on) ............................................................................................ 3A -36

ACTIVITY 3A - WORKSHEET F (Hands-on) ............................................................................................ 3A -37ACTIVITY 3A - WORKSHEET G (Written) ................................................................................................ 3A -38

ACTIVITY 3A - WORKSHEET H (Written) ................................................................................................ 3A -40

LESSON 3B: CNG FUEL SYSTEM COMPONENTS

CNG FUEL SYSTEM COMPONENTS ....................................................................................................... 3B -2

CNG Fuel Fill Valve ..................................................................................................................................... 3B -3Fuel Tanks .................................................................................................................................................. 3B -4

Solenoid Tank Valve E & F-Series ............................................................................................................. 3B -5

Solenoid Tank Valve - Contour .................................................................................................................... 3B -7Fuel Lines - E & F Series .......................................................................................................................... 3B -10Fuel Lines - Contour ................................................................................................................................. 3B -12Fuel Line Check Valve .............................................................................................................................. 3B -13

Quarter Turn Valve - Contour .................................................................................................................... 3B -14Fuel Filters ................................................................................................................................................ 3B -15

High Pressure Regulator .......................................................................................................................... 3B -17Compuvalve (as metering valve)............................................................................................................... 3B -19

Fuel Rails and Injector Sleeves ................................................................................................................. 3B -22

Multipoint Manifold Assembly - Contour .................................................................................................... 3B -24

CNG FUEL SYSTEM CONTROL MODULES AND INPUT/OUTPUT DEVICES ...................................... 3B -25Vehicle Communication Link (VCL) - 1999 Bi-Fuel Vehicles ..................................................................... 3B -26

Compuvalve (as Control Module) ............................................................................................................. 3B -27Description and Operation of Inputs ......................................................................................................... 3B -30

CNG Driver Selector Switch ..................................................................................................................... 3B -33Description and Operation of Outputs ....................................................................................................... 3B -35Bi-Fuel Relay Module ............................................................................................................................... 3B -36

CNG Wiring Connectors ........................................................................................................................... 3B -37

ACTIVITY 3B - WORKSHEET I (Hands-on) ............................................................................................. 3B -42ACTIVITY 3B - WORKSHEET J (Hands-on) ............................................................................................. 3B -43

ACTIVITY 3B - WORKSHEET K (Written) ................................................................................................ 3B -44ACTIVITY 3B - WORKSHEET L (Written) ................................................................................................. 3B -46

LESSON 4: COMMON BI-FUEL DIAGNOSIS AND SERVICE PROCEDURES

LPG/CNG BI-FUEL SYSTEM DIAGNOSTIC PROCEDURES ......................................................................4 - 2SYMPTOM-TO-SYSTEM-TO-COMPONENT-TO-CAUSE (SSCC) DIAGNOSTIC STRATEGY ....................4 - 3SERVICE AREA PRECAUTIONS.................................................................................................................4 - 5INTRODUCTION TO BI-FUEL VEHICLE SERVICE PROCEDURES ...........................................................4 - 6

PRELIMINARY DIAGNOSTIC STEPS ..........................................................................................................4 - 7Bi-Fuel System DTC Indications ...................................................................................................................4 - 8

SERVICEPUBLICATION NAVIGATION 4 - 10

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CONTENTS

ACTIVITY 4 - WORKSHEET M (Hands-on) ................................................................................................4 - 24ACTIVITY 4 - WORKSHEET N (Hands-On) ...............................................................................................4 - 26

ACTIVITY 4 - WORKSHEET O (Written) ....................................................................................................4 - 28ACTIVITY 4 - WORKSHEET P (Written).....................................................................................................4 - 30

LESSON 5A: UNIQUE LPG BI-FUEL DIAGNOSIS AND SERVICE

LPG CONTAMINATION ............................................................................................................................. 5A - 2FUEL SYSTEM BLEEDING PROCEDURES............................................................................................. 5A - 3

CHARGING THE FUEL LINES .................................................................................................................. 5A - 4FUEL LINE REPLACEMENT ..................................................................................................................... 5A - 5

Coolant System Leak Testing .................................................................................................................... 5A - 6

OFFLOADING PROPANE ......................................................................................................................... 5A - 7

ACTIVITY 5A - WORKSHEET Q (Hands-on) ........................................................................................... 5A - 10ACTIVITY 5A - WORKSHEET R (Written) ............................................................................................... 5A - 12

ACTIVITY 5A - WORKSHEET S (Written) ............................................................................................... 5A - 14

LESSON 5B: UNIQUE CNG BI-FUEL DIAGNOSIS AND SERVICE

CNG CONTAMINATION ............................................................................................................................. 5B -2FUELING CNG BI-FUEL VEHICLES .......................................................................................................... 5B -3

Fuel System Bleeding Procedures.............................................................................................................. 5B -5SOLENOID TANK VALVE DIAGNOSTICS .................................................................................................. 5B -6

FUEL SYSTEM VENTING .......................................................................................................................... 5B -7FUEL LINE SERVICE ................................................................................................................................. 5B -9Solenoid Tank Valve Manual Bypass Contour ........................................................................................ 5B -13

Solenoid Tank Valve Repair - Contour ....................................................................................................... 5B -15COALESCENT FILTER SERVICE ............................................................................................................ 5B -17

FUEL INJECTOR CLEANING .................................................................................................................. 5B -18PRESSURE REGULATOR FILTER SERVICE .......................................................................................... 5B -19

FUEL FILL VALVE FILTER........................................................................................................................ 5B -20

ACTIVITY 5B - WORKSHEET S (Written) ................................................................................................ 5B -22

ACTIVITY 5B - WORKSHEET T (Written)................................................................................................. 5B -25ACTIVITY 5B - WORKSHEET U (Hands-on) ............................................................................................ 5B -26

APPENDIX 1: LPG SAFETY APPENDIX

APPENDIX 2: CNG SAFETY APPENDIXAPPENDIX 3: AFV PARMETER IDENTIFICATION (PID)APPENDIX 4: NGS SUPPLEMENTGLOSSARY1996-1998 BI-FUEL VEHICLE SUPPLEMENTTOOL LIST

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CONTENTS

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DAY ONE INTRODUCTION AND PREREQUISITE REVIEW

Introduce the Ford Alternative Fuel

Curriculum

Administer the prerequisite review

Introduction to Alternative Fuel Curriculum

Prerequisite Review

CONTENTSOBJECTIVES

INTRODUCTION AND PREREQUISITE REVIEW

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DAY ONEINTRODUCTION AND PREREQUISITE REVIEW

Courses of the Alternative Fuel Vehicle (AFV) Curriculum

The Alternative Fuel Vehicle Curriculum consists of six courses related to Alternative Fuel Vehicle (AFV)

diagnosis and service. With the exception of the Ford Electric Ranger Course, each course in the curriculum

is a building block for the next course in the curriculum.

This curriculum is designed for technicians who want to learn the methods and techniques to properly

diagnose and service AFV systems and components.

Curriculum Goals

The goals of this curriculum are as follows:

id h i i bl h i i G S O

Alternative Fuel Vehicle New Generation STAR Web-Based Training - Course CodeWB31S09W0(Optional for Ford Dealership Technicians, Mandatory for Fleet Technicians,)

Alternative Fuel Handling Safety Web-Based Training - Course CodeWB 31S10W0(Mandatory for all Technicians)

Flexible Fuel Vehicle Web-Based Training - Course CodeWB 31S11W0(Mandatory for Ford Dealership Technicians, Optional for Fleet Technicians)

Ford Bi-Fuel CNG/LPG Vehicle (3-Day) Instructor-Led Training - Course Code31S13T0

Ford Dedicated CNG Vehicle (2-Day) Instructor-Led Training- CourseCode 31S14T0

Ford Electric Ranger Instructor-Led Training- Course Code 34N07T0(Optional for all Technicians)

(Mandatory for Ford Dealership Technicians, Optional for Fleet Technicians)

(Mandatory for Ford Dealership Technicians, Optional for Fleet Technicians)

ALTERNATIVE FUEL VEHICLE CURRICULUM MAP

ALTERNATIVE FUEL VEHICLE (AFV) CURRICULUM

Ford Bi-Fuel CNG Vehicle (2-Day)Instructor-Led Training - Course Code

31F16T0 (Fleet Technicians Only)

Ford Bi-Fuel LPG Vehicle (2-Day)Instructor-Led Training - Course Code

31F17T0 (Fleet Technicians Only)

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Ford Bi-Fuel Vehicle Instructor-Led Course Description

This is the first instructor-led course in the Alternative Fuel Vehicle Curriculum. It is a three-day course

facilitated by an instructor. This course is designed to provide hands-on opportunities for technicians to learn

and improve their skills with respect to utilizing tools and equipment; and to apply knowledge learned in

previous curriculum courses.

Course Terminal Objectives

Using the information and activities provided by this course the technician will:

accurately diagnose and repair Alternative Fuel Vehicle concerns using the appropriate tools and

equipment.

employ appropriate methods and techniques when servicing Alternative Fuel Vehicle systems and

components.

Audience

This course is designed and intended for Ford Motor Company dealership technicians who are enrolled

in the STST Alternative Fuel Vehicle Curriculum. Additionally, this course is also designed for trainingservice technicians of Ford Designated Fleets

Course Prerequisites

A technician taking this course should have the following prerequisite skills, knowledge and/or

experience:

Automotive Electrical 34S14T0

Automotive Electronics 34S19T0

Engine Performance Theory and Operation 31S07T0

Engine Performance Diagnosis and Testing 31S10T0

Additionally, technicians attending this course must have completed the following:

Alternative Fuel Vehicle New Generation STAR Web-Based Training (Mandatory for Fleet Techni-

cians, optional for Ford Dealership Technicians).

Alternative Fuel Safety Web-Based Training (Mandatory for all Technicians)

Flexible Fuel Vehicle Web-Based Training (Mandatory for Ford Dealership Technicians).

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Evaluation

Hands-on skills and course related knowledge is evaluated on the afternoon of the third day.

Hands-on evaluations will be conducted with exercises in: alternative fuel vehicle system diagnosis.

alternative fuel vehicle system service.

service publication CD-ROM/DVD navigation.

special tool usage.

In order topass the course, you must demonstrate acceptable skills at the evaluated hands-on exercises AND

you must answer at least 80% of the written post test questions correctly.

Student Guide

The Student Guide contains the worksheets used at the workstations for each of the three days. You must

complete each worksheet.

IMPORTANT: Actively participate in exercise reviews. This is your opportunity to ask questions and clear

up any areas that you may not fully understand.

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Service needs courteously identified, accurately recorded on Repair Order, and verified with customer.

Standard 4

Vehicles Serviced Right on the First Visit:

Service status provided within one minute of inquiry.

Vehicle ready at agreed upon time.

Thorough explanation of work done, coverages and charges.

The technician is the most important player when it comes to Standard 4.

Fix It Right the First Time, on Time

Why:

Customers tell us Fixing It Right the First Time, On Time is one of the top reasons they would decide to

return to a dealer to buy a vehicle and get their vehicles serviced.

Technician Training

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.

SERVICE STANDARDS

Mission Statement

All dealership personnel will treat every customer as a potential lifetime purchaser, communicating aprofessional image that embraces honesty and concern for customer wants and needs.

Dealer-to-Customer Service Standards

Appointment available within one day of the customers requested service day.

Write-up begins within four minutes of arrival.

Technicians Role

The technicians role is to acquire the skills and knowledge for competency in your specialty via:

FMT (self-study)

FORDSTAR Network (new model and curriculum)

New Model (self-study and instructor-led)

STST (instructor-led)

Web-Based Training (self-study)

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1. The vehicle and engine selection screen is necessary when using which of the following?A. Digital measurement systems.

B. Diagnostic data link.

C. New Generation STAR Setup.

D. Internal systems tests.

2. If there is an arrow at the right bottom of the menu screen it indicates which of the following?

A. There are more menu selections below.B. There are more menu selections above.

C. The NGS is in digital measurement mode.

D. The NGS is in active command mode.

3. A list of available control modules can be viewed by entering:

A. diagnostic data link.

B. generic OBDII functions

C. internal system tests

D. special functions

4. To retrieve DTCs you should select which of the following?

A. Diag test modes.

B. Data link diagnostics.C. View rec areas.

D. Internal systems tests.

5. A DTC received during a KOEO/KOER on-demand self-test is:

PREREQUISITE REVIEW

Introduction

This course begins with a review of the content covered in the prerequisite web-based courses. The review isdesigned to help you recall the key points and basic concepts of these courses. Comprehension of these key

points and concepts is essential to being successful in this course.

Directions: Select the best answer for the questions listed on the following pages.

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6. What connector is the NGS connected to on an AFV when retrieving DTCs?

A. Powertrain control module (PCM) connector.B. Data link connector (DLC).

C. Alternative fuel vehicle (AFV) module.

D. At the C4008 connector.

7. Continuous DTCs (memory codes) can be caused by:

A. a fault that has occurred, but may not be occurring now.

B. a fault that is occurring now.

C. both a and b.

D. neither a nor b.

8. _______ enables you to view input signals and output commands.

A. Diag test modes

B. PID data monitor & recordC. Active command mode

D. DTC library

9. The sampling rate at which the NGS can operate is directly affected by _______

A. the PID priority.

B. the number of PIDs selected.

C. the number of DTCs.

D. the type of DTCs.

10. PIDs can be selected by using which of the following methods?

A. Individual.

B. Groups.

C. Individual and groups.

D. Individual and blocks.

11. Once the NGS begins capturing data, the data will continue to be captured until:

A. CANCEL is pressed.

B button 7 on the numeric keypad is pressed

PREREQUISITE REVIEW (continued)

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13. When servicing a bi-fuel AFV always retrieve _______ first.

A. base vehicle DTCs

B. AFV DTCsC. fuel system DTCs

D. electrical system DTCs

12. The Active command mode:

A. prioritizes PIDs.B. allows you to link with vehicle control modules.

C. tests the operation of the module communication networks.

D. tests the modules ability to control selected ouputs.

14. A vehicle with a 3000 psi fuel storage system can be refilled with which of the following?

A. A 3000 psi pump.

B. A 3600 psi pump.

C. Either A or B.

D. Neither A nor B.

15. Incorrect use of the Contour manual lockout/manual bypass may cause which of the following?

A. A fuel leak.

B. Excess pressure.

C. Poor operating conditions.

D. None of the above.

16. You should never service a component on a bi-fuel CNG vehicle:A. when there is gasoline in the tank.

B. when there is pressure in the CNG fuel lines.

C. when the vehicle is in gasoline mode.

D. when the compuvalve is open.

17. If a CNG vehicle is parked in the shop and natural gas is accidentally released it would accumulate

in which of the following areas?

A. In the vehicle.B. Near the floor.

C. Near the ceiling.

D. None of the above.

18. What must be done prior to servicing the CNG fuel tank on a bi-fuel vehicle ?


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19. If a LPG vehicle is parked in the shop and propane is accidentally released, it would accumulate in

which of the following areas?A. In the vehicle.

B. Near the floor.

C. Near the ceiling.

D. None of the above

20. If a LPG bi-fuel vehicle requires painting, and the vehicle will be placed in a paint oven, what

must be done to the LPG tank?

A. It must be covered.B. It must be vented.

C. It must be removed.

D. The vehicle cannot be placed in a paint oven.

21. When performing a liquid leak detection test, dishwashing soap may be used to identify leaks?

A. Yes.

B. No.

C. On CNG vehicles only.

D. On LPG vehicles only.

22. Which of the following must be performed prior to servicing a propane fueled vehicle?

A. The manual shut-off valve must be opened.

B. The manual shut-off valve must be closed.

C. The pressure relief tank valve must be opened.

D. The pressure relief tank valve must be closed.

23. Which of the following is a major difference between ethanol and gasoline?

A. Gasoline is flammable.

B. Ethanol is more chemically reactive.

C. Ethanol is combustible.

D. All of the above.

24. Which of the following must never occur when working on a FF vehicle?

A. Take medication for the treatment of alcohol abuse.

B. Drink ethanol.C. Inhale large quantities of ethanol.

D. All of the above.

25. If fuel ethanol gets on your skin, you should:

A seek immediate medical attention


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NOTES

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DAY ONE LESSON 1: INTRODUCTION TO BI-FUEL VEHICLES

Upon completion of this lesson the student

will be able to:

Identify advantages of bi-fuel LPG/CNG/

gasoline vehicles.

Explain the differences of various types of

alternative fuels.

Describe changes to base vehicle

components on bi-fuel vehicles.

Explain changes to bi-fuel vehicle

operating strategies.

Introduction to Bi-Fuel Vehicles

Advantages of Bi-Fuel Vehicles

Alternative Fuels Comparison

Identification of Ford Bi-Fuel Vehicles

Changes to Base Vehicle Components on LPG/CNG Bi-Fuel Vehicles

Changes to Base Vehicle Operating Strategies

Supplemental Information on AFVs

CONTENTSOBJECTIVES

LESSON 1: INTRODUCTION TO BI-FUEL VEHICLES

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LESSON 1: INTRODUCTION TO BI-FUEL VEHICLES DAY ONE

INTRODUCTION TO BI-FUEL VEHICLES

Ford Clean-Earth Logo

According to the U.S. Environmental Protection Agency, more than 80 million Americans live in counties

that have unhealthy ground-level ozone levels.

In an effort to reduce these pollutant levels, many steps are being taken. One of these steps is to effectivelyuse alternative energy for vehicle fuels.

Ford Motor Company is a leader in the development and introduction of alternative fueled vehicles. For more

than two decades Ford has developed cutting edge technology to enable the effective use of alternative fuels.

The Ford commitment to maintaining a clean environment has led to the cleanest running, most efficient, and

technologically advanced alternative fueled vehicles in the world.

A bi-fuel vehicle is one that can run on two types of fuel. Ford produces bi-fuel vehicles that can run on eitherliquefied petroleum gas (LPG) or gasoline, and compressed natural gas (CNG) or gasoline. This three-day

training class will cover theory, operation, components, diagnosis, and service of bi-fuel vehicles. The

vehicles covered in this course include:

Art 1-1

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The reason bi-fuel vehicles were selected over a pure propane or natural gas vehicle is simple; convenience

and flexibility. While liquefied petroleum gas (LPG) (the commercial designation for propane) and natural

gas is available in most areas of the country, there are situations and circumstances where its availability is

limited. Ford, in an effort to provide its customers with maximum flexibility while reducing exhaust

emissions, provides vehicles that can operate on either conventional gasoline or LPG, or conventional

gasoline or CNG.

Advantages of Bi-Fuel Vehicles

Liquefied Petroleum Gas (LPG) and Compressed Natural Gas (CNG) Logos

During gasoline operation, vehicle systems operate conventionally. Components and their operation are the

same as would be found on normal gasoline-powered vehicles.

The unique aspect of Ford bi-fueled vehicles is the method in which the alternative fuel system is integrated

into the conventional systems to provide optimum performance for all vehicle operations.

A bi-fuel vehicle provides customers the convenience of being able to use either alternative fuel or gasoline

for vehicle fuel. This flexibility is essential for customers that operate their vehicles in areas where LPG or

CNG equipped fueling stations are not readily available.

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Alternative Fuel Comparison Table

The following table compares the characteristics of Propane, Compressed Natural Gas (CNG), Methanol, and

Ethanol to Gasoline.

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Identification of Ford Bi-Fuel Vehicles

1FTEF25Z5VLA00001Eighthletter Z in VIN indicates factory-installed bi-fuel prep vehicle.

Typical Bi-Fuel Prep Vehicle Identification Number (VIN)

Identification of a factory-manufactured Ford bi-fuel vehicle can be made using the vehicle identification

number (VIN).

The eighth digit/letter (reading left to right) of the VIN will be a Z for all factory-manufactured Ford bi-

fuel vehicles.

Additionally, a variety of Warning, Caution and Instruction labels are provided on the vehicle in critical areas

of the propane and driver control systems.

Art 1-5

LESSON 1 INTRODUCTION TO BI FUEL VEHICLES DAY ONE

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Changes to Base Vehicle Components on LPG/CNG Bi-Fuel Vehicles

LPG and CNG have different combustion characteristics than gasoline. Since both have higher octane

ratings than gasoline (see chart in this lesson) they burn more slowly than gasoline. For this reason,

engine timing must be advanced over base vehicle timing to allow for complete combustion of the fuel.

Additionally, both LPG and CNG are dry fuels. They contain few of the lubricating qualities of

gasoline. This can cause more wear on an engine.

In order to ensure that vehicles that operate on LPG and CNG have the same service life and handling

characteristics of a conventional vehicle, certain changes have been made to other vehicle components.

Changes to the engine include:

Intake and exhaust valve seat inserts.

Revised and hardened intake valve seats.

Stress-relieved (flame hardened) valves.

Corrosion resistant intake valves.

Positive valve rotation during operation.

Different pistons are used in the 4.6L engine (Crown Victoria only) to increase the compression ratio.

Changes to the chassis include:

Upgraded suspension system to accommodate the weight of the additional fuel tanks.

Depending upon the model:

Filler door may be widened to accommodate the extra fuel-fill port.

An additional fuel door may be installed to accommodate the extra fuel-fill port.

It is important to be aware of these changes, in the event that any of these components require

replacement during vehicle service.

DAY ONE LESSON 1 INTRODUCTION TO BI FUEL VEHICLES

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Changes to Base Vehicle Operating Strategies

OBD II operating strategies have been relaxed for bi-fuel vehicles. This is due to the unique operating

characteristics of bi-fuel vehicles.

The following table provides information on specific changes to bi-fuel operating strategies.

OBD II Diagnostic Base Gasoline Bi-Fuel Vehicle Bi-Fuel Vehicle

Monitor Vehicle On Gasoline On Alt. Fuel

Catalyst Monitor Enabled Enabled Disabled

Misfire Monitor Enabled Enabled Disabled

HO2S Monitor Enabled ----------- Disabled

Lack of Switching (US & DS) Enabled Enabled DisabledAmplitude Response Test (US) Enabled Enabled (relaxed criteria)* DisabledHeater Current Monitor (US & DS) Enabled Enabled DisabledDownstream Activity Test Enabled Enabled (relaxed criteria)* Disabled

EGR Monitor Enabled Enabled (relaxed criteria)* Disabled

Fuel System Monitor Enabled Enabled (relaxed criteria)* Disabled

Secondary Air Monitor Enabled --------------- Disabled

Evaporative Monitor Enabled Enabled Disabled

Component Monitor Enabled Enabled Partially Enabled

2-Volt Test (TP/MAF) Enabled Enabled DisabledFuel Pump Test Enabled Enabled DisabledIdle Speed Control Test Enabled Enabled Disabled

Purge Flow Checks Enabled Enabled DisabledAll Others Enabled Enabled Enabled

* Relaxed criteria has been deleted beginning 2001 MY.

US = Upstream, DS = Downstream, TP =Throttle Position, MAF = Mass Air Flow

LESSON 1: INTRODUCTION TO BI FUEL VEHICLES DAY ONE

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Supplemental Information On Alternative Fuel Vehicles

There are many places where supplemental information can be obtained on AFVs. The following list provides

various organizations, phone numbers, and websites where information is available for AFVs.

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DAY ONE LESSON 2A: INTRODUCTION TO LPG BI-FUEL VEHICLES

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DAY ONE LESSON 2A: INTRODUCTION TO LPG BI FUEL VEHICLES


will be able to:

Identify Bi-Fuel LPG Theory of

Operation.

Explain the fuel pressure of the LPG Bi-

Fuel System.

Describe the basic function of the

components of the LPG Bi-Fuel System.

Bi-Fuel LPG Fuel System Theory of Operation

CONTENTSOBJECTIVES

LESSON 2A: INTRODUCTION TO LPG BI-FUEL VEHICLES

LESSON 2A: INTRODUCTION TO LPG BI-FUEL VEHICLES DAY ONE

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LESSON 2A: INTRODUCTION TO LPG BI FUEL VEHICLES DAY ONE

1

2

3

5

8

9

10

11

4

6

7

The unique feature of LPG/gasoline bi fuel vehicles is the LPG fuel system

BI-FUEL LPG FUEL SYSTEM THEORY OF OPERATION

Typical LPG Fuel System

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Art 2A-1


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DAY ONE

To facilitate communication, a Vehicle Communications Link (VCL) is provided to exchange data with the

Powertrain Control Module (PCM).

On 1999 MY (and earlier) the VCL is a separate module.

On 2000-2002 the VCL is integrated into the compuvalve.

BI-FUEL LPG FUEL SYSTEM THEORY OF OPERATION


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1

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3

4

8

9

10

11

7

6

12

13

14

2

BI-FUEL LPG FUEL SYSTEM THEORY OF OPERATION (continued)

LPG Fuel System Schematic

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Art 2A-2


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BI-FUEL LPG FUEL SYSTEM THEORY OF OPERATION (continued)

The LPG fuel system on the bi-fuel vehicle operates as follows:

Liquid propane from the fuel storage tank (at pressure up to 312 psi @ 650 F) flows through themanual valve and a special fuel filter to the fuel lock-off solenoid located on the vaporizer (F150/

250).

On Super Duty Vehicles only (F350/550) liquid propane from the fuel storage tank (at pressure up to 300

psi) flows through the electric fuel tank shut-off valve (located on the fuel tank) to the fuel selector

solenoid, which is connected to both vehicle fuel tanks (on Super Duty vehicles that have multiple fuel

tanks). Fuel from the selected tank then flows to the fuel lock-off solenoid (located in the fuel line just

before the vaporizer).

Note: LPG fuel tank shut-off valves on Super Duty are electrically controlled, however, they also have a

manual shut-off feature integrated into the valve.

When the fuel lock-off solenoid is open, liquid propane flows into the vaporizer.

The two-stage regulator mechanism (internal to the vaporizer) reduces pressure (from tank pressure to

approximately 45 psi) causing the LPG to change into a gaseous state. It also provides the gaseous

propane at a consistent operating pressure to the computerized metering valve (compuvalve).

Additionally, a heat exchanger inside the vaporizer uses heat from the engine coolant to help with con-verting the LPG from a liquid into a gaseous state.

The compuvalve electronically meters fuel according to demand and sends signals to the PCM, which in

turn controls spark timing advance for optimum driveability and emissions.

A combination of sensors and inputs from the PCM are used to dynamically monitor the engine operating

environment to optimize fueling and ignition and provide closed loop control of fueling.

From the compuvalve, fuel flows through a low-pressure fuel line and is introduced into the intake

system through the fuel injector sleeves.

When propane is selected, the compuvalve intercepts the base vehicle fuel gauge signal and substitutes a

signal from a float style sensor in the propane fuel tank. The compuvalve then sends fuel level signals

through the J1850 network (circuits 914 and 915) to the Hybrid Electronic Control (HEC) module, which

in turn sends fuel level information to the fuel gauge.

In the gasoline mode, the normal fuel level sensor signal is sent to the gauge.

LPG operation requires engine coolant temperature (ECT) or cylinder head temperature (CHT) above 13

F (-11 C) for starting.

LPG operation requires a minimum fuel rail temperature (FRT) of (minus) -13 F (-25 C) for

vehicle operation.


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NOTES

DAY ONE ACTIVITY 2A

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The purpose of this activity is to:

Reinforce the knowledge that the student

has acquired from Lessons 1 and 2A.

Allow the student to review detailed

information found in Lessons 1 and 2A.

Allow the student to locate and identify

LPG fuel system components.

Review LPG fuel system safety prior to

beginning hands-on diagnostic and service

procedures.

Activity 2A - Worksheet A (Hands-On)

Activity 2A - Worksheet B (Written)

Activity 2A - LPG Safety Quiz (Written)

CONTENTSOBJECTIVES

ACTIVITY 2A

ACTIVITY 2A DAY ONE

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ACTIVITY 2A - WORKSHEET A (Hands-On)

LPG SYSTEM COMPONENT LOCATIONSTUDENT ANSWER SHEET

Directions: Using the information in your Student Reference Guide, go to the classroom vehicle and

write the letter/number of the component next to its name on the list below.

_________ Vaporizer

_________ Fuse and Relay Module

_________ Vaporizer Coolant Line

_________ Vaporizer Vent Hose

_________ Compuvalve and VCL Module

_________ Cold Start Relay

_________ Fuel Tank

_________ Manual Shut-Off Valve

_________ Fuel Fill Valve

_________ Selector Switch and Light

_________ Fuel Filter

DAY ONE ACTIVITY 2A

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ACTIVITY 2A - WORKSHEET B (Written)

LPG SYSTEM OPERATIONSTUDENT ANSWER SHEET

Directions: Using the information you have learned and your Student Reference Guide, answer the

following questions.

1. What is a bi-fuel vehicle?

PAGE #______

2. What year and model LPG bi-fuel vehicles will be covered in this training course?

PAGE #______

3. Why did Ford decide to market bi-fuel vehicles rather than pure propane vehicles?

PAGE #______

4. What is the specific gravity of propane?

PAGE #______

5. How can you identify a factory-manufactured Ford bi-fuel vehicle?

PAGE #______

6. What is the phone number of the National Alternative Fuels Hotline?

PAGE #______

7. When operating on alternative fuel, the catalyst monitor of a bi-fuel vehicle is (circle one) ENABLED or

ENABLED (RELAXED CRITERIA) or DISABLEDPAGE # ______

8. What are the major components of the LPG bi-fuel system?

ACTIVITY 2A DAY ONE

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END OF WORKSHEET

ACTIVITY 2A - WORKSHEET B (continued)

LPG SYSTEM OPERATIONSTUDENT ANSWER SHEET

9. What solenoid must be open for liquid propane to flow into the vaporizer?

PAGE # ______

10. What is the source of the heat that is used to convert liquid propane into gas?

PAGE # ______

11. What component electronically meters fuel according to demand and sends signals to the PCM for the

control of spark timing advance?

PAGE # ______

12. How is the vehicle fuel gauge used to indicate LPG fuel level when operating in the LPG mode?

PAGE # ______

DAY ONE ACTIVITY 2A

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ACTIVITY 2A - LPG SAFETY QUIZ (Written)

STUDENT ANSWER SHEET

Directions: Using the information you have learned from the Alternative Fuel Vehicle Fuel Handling and

Safety Web-Based Course, answer the following questions. NOTE: There is a Safety Appendix at the rear of

this Student Reference Guide that also can be used for reference.

1. What organization sets standards for the design and building of propane fuel systems in the U.S.?

PAGE # ______

2. What standard do many states and provinces regard as law?

PAGE # ______

3. List three sources of ignition that may be encountered in your service area that must be avoided when working

on LPG powered vehicles?

PAGE # ______

4. When servicing an LPG fuel system in a building, what must be done?

PAGE # ______

5. What may happen if a propane tank is exposed to high ambient temperatures?

PAGE # ______

6. What should be done if you detect the odor of propane or a quantity of propane gas is present in an area? What

steps should you take?

PAGE #

ACTIVITY 2A DAY ONE

ACTIVITY 2A LPG SAFETY QUIZ (W i )

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ACTIVITY 2A - LPG SAFETY QUIZ (Written)

STUDENT ANSWER SHEET (continued)

7. When can shop air be used to force propane fuel from the LPG fuel system?

PAGE # ______

8. What type of paint drying methods should be used on LPG bi-fuel vehicles?

PAGE # ______

9. What valve must always be closed before performing any LPG fuel system service?

PAGE # ______

10. If the manual shut-off valve is opened too quickly, what may occur?

PAGE # ______

11. Bi-fuel vehicle LPG fuel systems can only be modified under what circumstances?

PAGE # ______

12. What type of replacement parts must be utilized on LPG fuel systems?

PAGE #______

13. In the event a person becomes ill from inhaling propane, what action should immediately be taken?

PAGE # ______

DAY ONE LESSON 2B: INTRODUCTION TO CNG BI-FUEL VEHICLES

LESSON 2B INTRODUCTION TO CNG BI FUEL VEHICLES

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Bi-Fuel CNG Fuel System Theory of Operation

CONTENTSOBJECTIVES

LESSON 2B: INTRODUCTION TO CNG BI-FUEL VEHICLES


will be able to:

Identify Bi-Fuel CNG Theory of

Operation.

Explain the fuel pressure of the CNG Bi-

Fuel System.

Describe the basic function of the

components of the CNG Bi-Fuel System.

LESSON 2B: INTRODUCTION TO CNG BI-FUEL VEHICLES DAY ONE

BI FUEL CNG FUEL SYSTEM THEORY OF OPERATION

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5

1

2

3

4

6

79

10

11

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The CNG fuel system major components include:

A regulator.

A combined metering valve and computer (compuvalve). Incorporated into the compuvalve are absolute

(f l d i t k if ld) d f l t t

BI-FUEL CNG FUEL SYSTEM THEORY OF OPERATION

Typical CNG Bi-Fuel Component Location


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BI FUEL CNG SYSTEM THEORY OF OPERATION (continued)

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BI-FUEL CNG SYSTEM THEORY OF OPERATION (continued)

CNG Fuel System Schematic

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The solenoid tank valves will initially only be activated for one second and then will be turned off unless

the PCM receives a PIP signal indicating that the engine is turning.

This allows high pressure natural gas to enter the fuel lines.

The high pressure natural gas passes through the high pressure fuel lines, past the quarter-turn valve

and into the high-pressure (coalescent) filter.

In the high pressure filter, water and particulate contaminates are removed from the natural gas.

After leaving the filter the natural gas flows into the high pressure regulator. The regulator provides a

consistent operating fuel pressure (100 psi) for the system.

From the regulator CNG passes to the computerized metering valve (compuvalve).

The compuvalve electronically meters fuel according to demand and sends signals to the PCM, which

in turn controls spark timing advance for optimum driveability and emissions.

A combination of sensors and inputs from the PCM are used to dynamically monitor the engineoperating environment to optimize fueling and ignition and provide closed loop control of fueling.

The compuvalve uses speed density calculations for both fuel flow and air flow while adjusting the air/

fuel mixture.

Adjustments occur for each spark event.

From the compuvalve, fuel flows through fuel rails and is introduced into the intake system through the

fuel injector sleeves.

The fuel tank pressure (FTP) sensor provides the compuvalve with CNG pressure information. Thisinformation allows the compuvalve to drive the base vehicle fuel gauge during CNG operation.

The CNG fuel system on bi-fuel vehicles operate as follows:

When the ignition switch is turned to the run or start position, the PCM energizes the fuel shut-off relay. The fuel shut-off relay in turn sends voltage to the solenoid tank valves, causing them to open.



CNG FUEL SYSTEM PRESSURES

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CNG FUEL SYSTEM PRESSURES

CNG bi-fuel systems operate at very high pressures. However, these pressures will change as the fuel passes

CNG Fuel System Pressure Schematic

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2

7

9

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4

5

6


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CNG FUEL SYSTEM PRESSURES (continued)

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The high pressure fuel lines carry the CNG throughout their length to the coalescent filter.

Fuel in the coalescent filter will be at tank pressure (vehicle and MY dependent).

After leaving the coalescent filter, the fuel enters the pressure regulator.

The pressure regulator lowers the fuel pressure from tank pressure.

When the fuel leaves the pressure regulator its pressure will be at a nominal 100 psi.

It passes from the pressure regulator to the compuvalve through low-pressure fuel lines.

At the compuvalve, the fuel is metered to meet the engine requirements for the vehicle operating

conditions.

For this reason, pressure of the fuel leaving the compuvalve will vary. However, it will be significantly

lower than the 100 psi of pressure that entered the compuvalve.

This lower pressure fuel moves from the compuvalve to the fuel rails, injector sleeves, and then into the

engine intake.

CNG FUEL SYSTEM PRESSURES (continued)

DAY ONE ACTIVITY 2B

ACTIVITY 2B

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The purpose of this activity is to:

Reinforce the knowledge that the student

has acquired from Lessons 1 and 2B.

Allow the student to review detailed

information found in Lessons 1 and 2B.

Allow the student to locate and identifyCNG fuel system components.

Review CNG fuel system safety prior to

beginning hands-on diagnostic and service

procedures.

Activity 2B - Worksheet C (Hands-On)

Activity 2B - Worksheet D (Written)

Activity 2B - CNG Safety Quiz (Written)

CONTENTSOBJECTIVES

ACTIVITY 2B

ACTIVITY 2B DAY ONE

ACTIVITY 2B - WORKSHEET C (Hands-On)

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CNG SYSTEM COMPONENT LOCATIONSTUDENT ANSWER SHEET

Directions: Using the information in your Student Reference Guide, go to the classroom vehicle and writethe letter/number of the component next to its name on the list below.

__________ High-Pressure Regulator

__________ Fuse and Relay Module

__________ Regulator Coolant Line

__________ Compuvalve and VCL Module

__________ Coalescent Filter

__________ Tank Valve

__________ Fuel Fill Valve

__________ Selector Switch

__________ Fuel Tank Temperature Sensor

__________ High-Pressure Fuel Line

__________ Low-Pressure Fuel Line

__________ Quarter-Turn Valve

__________ Fuel Tank Pressure Sensor

DAY ONE ACTIVITY 2B

ACTIVITY 2B - WORKSHEET D (Written)

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1. Why does Ford offer customers the flexibility of bi-fuel vehicles?

PAGE# ________

2. What year and model CNG bi-fuel vehicles will be covered in this training course?

PAGE #______

3. What is the specific gravity of natural gas?

PAGE #______

4. How can you identify a factory-manufactured Ford bi-fuel vehicle?

PAGE #______

5. What changes have been made to the engine valves on a CNG bi-fuel vehicle?

PAGE #______

6. When operating on CNG, the misfire monitor of a bi-fuel vehicle is (circle one) ENABLED or ENABLED

(RELAXED CRITERIA) or DISABLED?

PAGE#________

7. What is the website for the Certified Compressed Natural Gas Cylinder Inspectors?

PAGE #______

8. What are the major components of the CNG fuel system on a bi-fuel vehicle?

CNG SYSTEM OPERATIONSTUDENT ANSWER SHEET

Directions: Using the information you have learned and your Student Reference Guide, answer the followingquestions.

ACTIVITY 2B DAY ONE

ACTIVITY 2B - WORKSHEET D (continued)

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9. If the PCM does not receive a PIP signal within 1 second of the ignition being turned on, what devices willbe automatically closed?

PAGE#________

10. What relay is energized when the ignition is turned on and sends voltage to the solenoid tank valves?

PAGE#________

11. The FTP sensor provides the compuvalve with pressure information. What does the compuvalve use this

information for?

PAGE#________

12. What are the pressures of the CNG as it moves from the fuel tank to the pressure regulator?

PAGE#________

END OF WORKSHEET

CNG SYSTEM OPERATIONSTUDENT ANSWER SHEET

DAY ONE ACTIVITY 2B

ACTIVITY 2B - CNG SAFETY QUIZ (Written)

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STUDENT ANSWER SHEET

Directions: Using the information you have learned from the Alternative Fuel Vehicle Fuel Handling and

Safety Web-Based Course, answer the following questions. NOTE: There is a Safety Appendix at the rear ofthis Student Reference Guide that also can be used for reference.

1. What organization sets the safety standards for natural gas?

PAGE#_______

2. What standards do many states and provinces regard as law for the design and building of CNG fuel

systems?PAGE#________

3. List three sources of ignition that may be encountered in your service area that must be avoided when

working on CNG fueled vehicles?

PAGE#________

4. Why must a vehicle be grounded when venting natural gas from its fuel tank?

PAGE#________

5. Ford Bi-Fuel CNG vehicles receive fuel at what pressures?

PAGE#________

6. What should be done if you detect the odor of natural gas?

PAGE#________

7. Since natural gas is lighter than air, where in a building is it more likely to become trapped?

PAGE#________

CONTINUED ON NEXT PAGE

ACTIVITY 2B DAY ONE

ACTIVITY 2B - CNG SAFETY QUIZ (Written)

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STUDENT ANSWER SHEET (continued)

8. What must be done before a CNG fueled vehicle can be dried in a paint oven?

PAGE#________

9. If a CNG fuel tank has been subjected to fire, what service must be performed?

PAGE#________

10. At what temperature will the tank insert melt if a tank is exposed to a fire?

PAGE#________

11. On an internal pressure relief device (PRD) type solenoid tank valve, the PRD can only be replaced as

part of the valve? (circle one) TRUE or FALSE

PAGE#________

12. Bi-fuel CNG fuel systems can only be modified under what circumstances?

PAGE#________

13. Can you refuel a 3600 psi bi-fuel vehicle at a pump that dispenses CNG at 3000 psi? (Circle one) YES or

NO

PAGE#________

14. Can you refuel a 3000 psi bi-fuel vehicle at a pump that dispenses CNG at 3600 psi? (Circle one) YES or

NO

PAGE#________

15. What type of hazard can be caused by incorrect operation of the solenoid tank valve with an external

pressure relief device?

PAGE#________

16. What type of replacement parts must be utilized on CNG fuel systems?

PAGE#________

17. In the event a person becomes ill from inhaling natural gas, what action should immediately be taken?

PAGE#

DAY ONE LESSON 3A: LPG BI-FUEL COMPONENTS AND SYSTEMS

LESSON 3A: LPG BI-FUEL COMPONENTS AND SYSTEMS

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CONTENTSOBJECTIVES


will be able to:

Describe LPG bi-fuel vehicle component

function.

Identify LPG bi-fuel vehicle component

location.

Explain LPG bi-fuel vehicle component

operation.

Describe possible symptoms of LPG bi-

fuel vehicle component concerns.

Identify LPG bi-fuel vehicle inputs and

outputs.

Explain LPG bi-fuel vehicle control

modules.

Describe LPG bi-fuel vehicle operating

strategies.

LPG Fuel System Components

LPG Control Modules and Input/Output

Devices

DAY ONELESSON 3A: LPG BI-FUEL COMPONENTS AND SYSTEMS

LPG FUEL SYSTEM COMPONENTS

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The LPG fuel system components on 1999 - 2002 Model Year (MY) LPG Bi-fuel vehicles are very similar.

However, as with most vehicle systems, changes have been made to improve performance and serviceability.

This lesson will describe the LPG fuel system components, their location, and operation. It will also describechanges to these components and unique characteristics for specific vehicles and model years.

The lesson will also contain a description of how these components operate within the vehicle LPG fuel

system, and the control system that enables the system to operate efficiently.


LPG Fuel Fill Valve

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COMPONENT FUNCTION

Enables vehicle to receive LPG fuel.

COMPONENT LOCATION

The LPG fill valve is located on the drivers side of the vehicle (in front fuel fill opening of the pickup box on

F-Series).

DESCRIPTION AND OPERATION

The fill valve allows the bi-fuel vehicle to receive LPG fuel.

It i d i d t fit t d d LPG hi l f li l

Typical LPG Fuel Fill Valve

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Art 3A-1


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LPG Fuel Tanks (E Series and F150/250)

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COMPONENT FUNCTION

To store pressurized LPG fuel.

COMPONENT LOCATION

At front of truck bed near passenger compartment.


In-Bed LPG Fuel Tank (F-Series)


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Art 3A-2


LPG Fuel Tanks (Super-Duty F350/550)

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1

COMPONENT FUNCTION

To store pressurized LPG fuel.

COMPONENT LOCATION

Left side of vehicle behind drivers door and aft tank is located beneath the rear of vehicle behind the

differential.


Tanks are constructed of welded steel.

Fuel flow from the tanks is controlled with an electric fuel tank shut-off valve.

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Super Duty Multiple Fuel Tank Configuration

Art 3A-3


LPG Fuel Tanks (continued)

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LPG is stored in the tank as a liquid. If the tank is exposed to high ambient temperatures, the liquid will

vaporize and expand, causing internal tank pressure to increase.

The tank relief valve opens when tank pressure exceeds 45 kPa (312 psi).

LPG fuel tanks are designed to only be filled to 80 percent of maximum capacity to allow for

expansion caused by ambient temperatures.

To prevent overfilling of the tank a stop-fill valve is used to shut off LPG flow into the tank once

maximum capacity has been reached.

The overflow (spitter) valve should be opened during refueling. This ensures that tank overfilling

does not occur in the event of a stop-fill valve failure. Refer to local fueling regulations.

POSSIBLE SYMPTOMS

Pressure relief valve opens venting fuel due to high ambient temperatures.

If the shut off valve is open too quickly after its been closed, the excess flow valve may cut off fuel flow to

fuel system. To correct this, close the shut off valve, listen for a slight click, then reopen it more slowly.

WARNING: A FAILURE OF THE STOP FILL VALVE WILL ALLOW OVERFILLING OF THE

FUEL TANK. THIS CAN CAUSE A DANGEROUS CONDITION OF FUEL OVER-

PRESSURIZATION. ALWAYS OPEN THE SPITTER VALVE DURING REFUELING TO

PREVENT THIS CONDITION.

LPG Fuel Tank Capacities

* 141 and 176 inch wheelbase vehicles** 102 and 165 inch wheelbase vehicles

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Art 3A-4


Fuel Tank Testing and Inspection

Fuel tank testing and inspections are specified and controlled by the AUTHORITY HAVING

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g p p y

JURISDICTION (the governmental body responsible for the enforcement of codes or the official or agency

designated by that body to exercise such a function). This includes the qualification of personnel and facilities

used for these purposes.

The propane fuel system must be visually inspected at 5 year intervals, starting with date of installation.

The recorded visual examination requalifies it for five years before the next qualification.

Certain types of damage to a tank may be repaired, provided that the tank is retested and recertified before

the tank is returned to service.

Inspections and repairs shall be made ONLY by qualified persons acceptable to the AUTHORITY HAVING

JURISDICTION.

WARNING: TANKS THAT DO NOT PASS THE INSPECTION CRITERIA MUST BEREPAIRED AND RETESTED OR REPLACED BEFORE THE VEHICLE ISRETURNED TO SERVICE USING PROPANE.

If damage to the tank is observed during maintenance or repair, the tank must be inspected, repaired, and

approved by qualified personnel. If the tank is rejected, the tank must be replaced before being returned to service.

Different jurisdictions have inspection requirements and specific labeling to record these inspection practices.

Failure to comply can cause the vehicle to be in violation of the established regulations.

BEFORE BEGINNING ANY INSPECTION OR REPAIR, CHECK WITH THE LOCAL AUTHORITY

HAVING JURISDICTION CONCERNING THE REQUIREMENTS FOR PERSONNEL, FACILITIES

AND PROCEDURES REQUIRED FOR THE AREA OF OPERATION.


LPG Fuel Level Float

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COMPONENT FUNCTION

Sends fuel level information to the fuel gauge.

COMPONENT LOCATION

Mounted inside the fuel tank.


The LPG fuel tank sending unit consists of a fuel level float and a fuel level sensor.

The float is attached to a counterbalanced pivot arm that pivots on a pin.

A gear on the pivot pin drives a pinion gear on a drive shaft.

Float arc is then converted to drive shaft rotation.

A drive magnet on the opposite end of the drive shaft is magnetically coupled to the external fuel level sensor.

The compuvalve monitors the voltage drop across the variable resistor of the fuel level float. It then uses this

information for fuel level calculations.

LPG Fuel Level Float

POSSIBLE SYMPTOMS

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Art 3A-5

WARNING: LPG FUEL LEVEL FLOAT IS NOT SERVICEABLE. REMOVAL OFTHE FUEL LEVEL FLOAT MAY RESULT IN SEVER PERSONAL INJURY.


Fuel Lines

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COMPONENT LOCATION

Fuel lines run from the fuel tanks to the various components of the LPG fuel system.COMPONENT FUNCTION

Carries pressurized fuel from the fuel tank to the various components of the fuel system.


Fuel lines transport pressurized fuel from the fuel tank to the fuel vaporization and metering components.

The fuel lines are seamless stainless steel and cloth reinforced rubber with crimped fittings. They are

designed specifically to handle LPG.

The fuel lines meet all United States and Canadian safety specifications.

Whenever connecting fuel line fittings, always use new copper washers, never reuse copper washers.

Typical LPG Fuel Line

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Art 3A-6


Vaporizer

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COMPONENT FUNCTION

V i LPG f l i i t th i

Typical Vaporizer

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Pressure is lower inside the vaporizer than in the fuel delivery system, which lowers the LPGs boiling point.

Vaporizer (continued)

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This reduction in pressure lowers the boiling point of the LPG causing it to begin vaporization.

The vaporizer is also connected to the engine cooling system via hoses. This allows engine coolant to flowthrough a heat exchanger within the vaporizer.

As the LPG passes through the heat exchanger, the heat from the engine coolant is transferred to the LPG,

completing the boiling process and completely vaporizing the fuel.

The vaporized fuel is then delivered to the compuvalve for injection into the engine.

When engine coolant is below 0C (32F), an electrical cold start heater is used in the vaporizer heat exchanger

to help vaporize the LPG.

The electrical cold start heater turns off when engine coolant is above 10C (50F).

The heater uses battery voltage and is activated by a signal sent from the compuvalve.

POSSIBLE SYMPTOMS

Incomplete vaporization of fuel causing rough running and hard starting.

Engine coolant leakage.


Electric Fuel Lock-off Solenoid

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COMPONENT FUNCTION

Prevents or allows fuel flow into the vaporizer.

COMPONENT LOCATION

F-Series vehicles - attached to the vaporizer at the inlet line.

Super Duty vehicles - remotely located on top of the engine connected to the

vaporizer inlet line.


The lock-off solenoid is an on/off solenoid that is closed when no voltage is being

received (engine off/gasoline operation). When closed, it prevents LPG from reaching the vaporizer.

During LPG operation, the solenoid receives a voltage signal from the fuel pump relay

when the compuvalve sends a signal to switch to LPG allowing fuel to flow into the

vaporizer

Electric Fuel Lock-off Solenoids

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Compuvalve (Fuel Metering Operation)

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COMPONENT FUNCTION (AS FUEL METERING DEVICE)

Uses preprogrammed strategies to control operation of LPG fuel system, then meters fuel flow going into

the engine.

COMPONENT LOCATION

Top RH side of engine.


The compuvalve utilizes two types of injectors to accurately meter fuel being sent to the injectors.

The metal-cased high flow injectors are on/off devices that provide high volumes of fuel when requiredduring cruise and acceleration.

The plastic-cased low flow injectors are pulse width modulated (PWM) and provide idle and trimming

fuel flow.

Compuvalve (1999 MY)

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Compuvalve (Fuel Metering Operation) (continued)

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The following is an example of how the injectors in the compuvalve combine to meter the correct amount of

fuel during vehicle operation. The injectors in the art above are numbered based on PID identification (called

out as the VLVE PIDs).

Assume that the vehicle is operating in a situation that requires 6360 CFH of LPG. The compuvalve may turn

on a combination of the following high flow injectors (see above art):

#6 providing 3360 CFH

#5 providing 1360 CFH

Example of Compuvalve Operation

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Art 3A-10


The low flow injectors (which are PWM controlled) would each provide 32.5 CFH of LPG (the other 65 CFH)

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Compuvalve (Fuel Metering Operation) (continued)

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by pulsing on and off to allow the addition of fuel into the injector sleeves.

The combination of this injector operation provides the 6360 CFH of LPG required.

To ensure full vaporization, engine coolant is sent through the compuvalve to warm the fuel.

POSSIBLE SYMPTOMS (Fuel Metering Operation Only)

Rough running caused by the use of contaminated fuel which can result in blocked or clogged injectors.

Incorrect fuel metering which can result in rich or lean fuel mixture.

Engine coolant leak.


Fuel Rails and Injector Sleeves

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COMPONENT FUNCTION

Introduces fuel into combustion chamber.

COMPONENT LOCATION Fuel rails - top left and right side of engine next to intake manifold.

Injector sleeves - top of engine beneath gasoline fuel injectors.



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Fuel Rails and Injector Sleeves


POSSIBLE SYMPTOMS

Fuel Rails and Injector Sleeves (continued)

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Fuel leakage caused by damaged o-rings.

Fuel leakage caused by installation of incorrect replacement injector sleeves (there are 2 different size brassand 1 size plastic injector sleeves).

The vehicle should be operated on gasoline for at least 1 tank every 60 days. Failure to do so may cause the

gasoline fuel injectors to clog.

Injector sleeve o-ring deterioration on high-mileage vehicles has been known to cause vacuum leaks and

rough engine operation.


LPG FUEL SYSTEM CONTROL MODULES AND INPUT/OUTPUT DEVICES

The advent of the microprocessor has revolutionized automotive control systems. The average control

module used on a Ford vehicle today is more powerful than the on-board computer used on the Apollo

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module used on a Ford vehicle today is more powerful than the on board computer used on the Apollo

missions that successfully landed men on the moon.

As with the powertrain control module (PCM), which controls base vehicle operations, bi-fuel vehicles have

control module(s) that are dedicated to LPG fuel system control.

All control modules use input devices to monitor vehicle operating conditions. The signals received by these

devices determine the modules operating strategy. It then modifies vehicle operation by sending control

signals to vehicle output devices.

The following pages contain a description of these modules and input/output devices.


Vehicle Communication Link (VCL) -1999 Bi-Fuel Vehicles

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COMPONENT FUNCTION

Facilitates communication between the compuvalve and the PCM to control operation of LPG fuel system.

COMPONENT LOCATION

RH side of passenger compartment beneath kick panel.


The VCL allows communication between the compuvalve and the PCM.

When the key is turned ON, the VCL tells the PCM which operating mode has been selected by the driver

(gasoline or LPG).

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Art 3A-12


Compuvalve (as Control Module)

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COMPONENT FUNCTION (AS CONTROL MODULE)

Uses preprogrammed strategies to control operation of LPG fuel system. Then meters fuel flow going into

the engine.

Beginning in the 2000 MY the VCL is incorporated into the compuvalve.

COMPONENT LOCATION

Top RH side of engine.


The compuvalve is a unique combination of a metering valve and control module.

The compuvalve monitors vehicle input sensor information provided to it from the PCM via the VCL.

The compuvalve then uses this information to meter LPG fuel and suggest spark advance to the PCM.

The PCM looks at the compuvalve recommendation, as well as data from other inputs, then advances the

engine spark timing as needed for best operation on LPG.

Compuvalve Control Module


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POSSIBLE SYMPTOMS

Failure to run on either or both LPG or Gasoline

Compuvalve (as Control Module) (continued)

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Failure to run on either or both LPG or Gasoline.

Rough running or hard starting on LPG.

Numerous other symptoms may occur due to incorrect compuvalve operation as a control module. Refer to

vehicle service publications for diagnosis and testing.


Inputs and Outputs - Bi-Fuel Vehicles (Propane Operation Only)

INPUTS OUTPUTS

ECT/CHT

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xxxxxxx

VSS

IAT

EGR

Powertrain

Control

Module (PCM)

Spark Advance

Gasoline Injectors

Signals Sentvia J 1850Network DataBus

Compuvalve

(2000 MY and

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vehicles have

VCL internal

to thecompuvalve)

RPM

TPSHO2S11

HO2S21

Dash Switch

FRPREAB

FRTMPABMAP

B +

Fuel Selector Light

Fuel Lock-Off Solenoid

LPG Injectors

Cold Start Heater Relay

Fuel Gauge

Gasoline Fuel Pump

MIL

Vehicle

Communication

Link (VCL)

Circuits G054and G056transmit andreceive wires (1999 MY)

Signals Sentvia J 1850Network DataBus

1999 MY

HEC Module (1999 MYd L t )

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xxxxxxxxxxx

ECT/CHT

Compuvalve


RPM:

Engine RPM signals are sent directly to the compuvalve (F-150 for 1999 MY only had RPM signals sent from

Description and Operation of Inputs

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Engine RPM signals are sent directly to the compuvalve (F 150 for 1999 MY only had RPM signals sent from

the crankshaft position (CKP) to the clean tach output (CTO) module. 2000 and later F-150s have RPM signalssent from the CKP to the compuvalve (with integrated CTO module).

The compuvalve then uses the RPM signal to determine the best vehicle operating strategy.

Throttle Position Sensor (TPS):

The TPS is hardwired to the compuvalve.

The compuvalve uses the TPS signals to help determine engine load and correct air/fuel mixture.

Heated Oxygen Sensors (HO2S11 and HO2S21):

Both HO2S are wired to the compuvalve.

The compuvalve uses these signals to determine the best fuel mixture for vehicle operating conditions.

Fuel Selector Switch:

On F and E - Series light trucks this is a single pole double throw switch mounted on the upper left side of

the instrument panel. Positions are GAS and ALT.

On Super Duty 350/450/550 vehicles this is a single pole triple throw switch mounted on the upper left sideof the instrument panel. Positions are GAS, LPG 1, and LPG 2.

It receives battery voltage from the compuvalve.

If this voltage is not returned to the compuvalve, the vehicle defaults to gasoline operation.

Fuel Rail Pressure Sensor (FRPREAB):

Located inside the compuvalve, this is a piezo-resistive pressure transducer that converts pressure into a

voltage signal. The compuvalve then uses this signal to adjust the injector combination according to supply pressure.

The FAP can be seen using the fuel pressure sensor (FRPREAB) PID of the N

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