Understanding Electronic Fuel Injection, Ignition and Engine Management

Written in the mid-1990s this publication has now been converted to PDF form and is available for the first time as a download. It was originally produced using a now obsolete word processor which had limitations that meant illustrations had to be grouped at the end of each chapter. Now converted to MS Word that format has been retained for expediency otherwise the process would have been far too protracted. There has been some minor editing of the text where thought necessary, but the work is substantially the same as the original and totals 238 pages.

It is still very relevant to EFI and ignition systems of the 1970 – 95 era but obviously does not deal with more recent OBD2 and later systems.

Please email aj6engineering@ntlworld.com using the subject line ‘EFI Book’ for details of how to purchase the complete download at an attractive price.

The contents and subject matter are detailed below.

Written and published by us this is THE book for anyone who wants a proper grasp of the subject. Describes how these systems evolved and builds on the basic principles from early Bosch D Jetronic Fuel Injection, the ancestor of them all, through to modern programmed systems encompassing ignition, idle speed control, self diagnostics and so on. Not only how they work but why they became necessary, how to make adjustments and how to trouble shoot them. Also deals with fuel handling, combustion, exhaust emissions, gas analysis diagnosis, etc. all in the same forthright manner. Over 100,000 words with many diagrams and illustrations.

Equally suitable for the professional technician or the enthusiastic amateur, the following list of contents describes all the subjects covered.

Chapter 1. THE FUNDAMENTALS – COMBUSTION, FUELLING, IGNITION, and
EXHAUST EMISSIONS.

The combustion process. Detonation, pre-ignition & pinking. Combustion chamber layout. What the engine expects from fuel and ignition systems. Emissions HC, CO, NOx etc. EGR, Lambda and LAF sensors. Catalysts. Lean burn. Economy. Evaporative loss control.

 

Chapter 2. FUEL HANDLING.

Basic principles. Tanks, breathers, vapour traps. Fuel pump and control. Recirculation principle. Twin tank systems. Pressure regulation. Pulsation damping. Injectors – construction, flow rates, failures. Single Point Injectors.

 

Chapter 3. THE AIRFLOW TRACT.

Intake ducting. Noise & resonance chambers. Variable geometry. Throttle assembly. Idle speed control. Over-run valves. Tuned ram manifolds. Injector location.

 

Chapter 4. EFI ELECTRICAL OPERATING PRINCIPLES.

Injector Pulses. Injector action in detail. Injector drive circuitry. Injection timing, sequential injection. Over-run cut off. Sensors. ECU principles. Analogue and digital differences. Fuel laws and maps. Interference screening.

 

Chapter 5. FIRST GENERATION ELECTRONIC INJECTION.

Bosch D Jetronic – ancestor of them all. Sensors. Triggering. Cold start injection. Jaguar V12 variant 3CU. Problem areas. Lucas Epitest.

Chapter 6. SECOND GENERATION EFI – BOSCH L JETRONIC AND FRIENDS.

L Jetronic principles. Flap airflow meter. Problem areas. LE Jetronic. Electronic idle speed control. Lucas L 4CU (Rover V8). Lucas P 6CU, 8CU (Jaguar V12, 3.6 XJS). Mercury Marine V6.

Chapter 7. THIRD GENERATION EFI – ELECTRONIC SOPHISTICATION.

Understanding microprocessor based systems. Adding features to the program. Memory, EPROMS, etc. Bits & Bytes. Sensor scanning. Practical mapping. Lucas 16CU (Jaguar V12). Idle speed control considerations and solutions. Hot wire airflow meter. LH Jetronic. Lucas hot wire (Rover Montego etc.) Adaptive memory. Fault detection. Limp home. Data logging. Lucas 13 & 14 CU (Rover V8). Lucas 26CU, 36CU (Jaguar V12). Single Point Systems, Bosch Monojetronic etc.

Chapter 8. THE IGNITION SYSTEM.

The contact breaker system – why it is no longer good enough. Early transistor assisted types. Triggering methods and pickups. Lucas Opus. Constant energy types. CDI. Programmed advance curves – influence on power, economy and emissions. Lucas digital. Ford DIS. Microprocessor systems. Knock sensors. Octane plug. Load sensing. Multiple and missing tooth triggering methods. Rover system. Bosch. Ford ESC 2. Marelli Digital. SAAB Direct Ignition.

Chapter 9. TRUE ENGINE MANAGEMENT – FUEL AND IGNITION ALL IN ONE.

Advantages of an integrated system. Basic principles. Bosch Motronic. Ford EEC1V – 2.9 & Zeta variants. Rover MEMS. Honda PCM-PI, V-Tec, LAF sensor, Dual Point Injection. Toyota TCCS. GM system. Lucas 9CU (Jaguar 3.6). Lucas 15CU (Jaguar 4.0). Things to come. Drive by wire. Advanced fault detection and diagnosis. A note of caution.

Chapter 10. DIAGNOSIS, FAULT FINDING AND ADJUSTMENTS THE TRADITIONAL WAY.

Basic approach to diagnosis. Dead Engine faults. Running engine faults. Exhaust gas analysis as an aid to diagnosis. Catalysts. Spark plugs. Fuel handling faults. Air tract faults. Electrical faults. Ignition.

Chapter 11. DIAGNOSIS, FAULT FINDING AND ADJUSTMENTS THE HIGH-TECH WAY.

Trouble in store? – the drawbacks of high technology. Manufacturer’s plug-in diagnostic techniques. Typical evolution path – Rover FastCheck-Cobest-Microcheck-TestBook. Similar solutions for the independent garage – Survey of scanners – Datacheck, Code Reader, AutoScan, Laser 2000, Snap-On MT2500, Crypton CheckMate, etc. The break out box. Oscilloscopes.

Chapter 12. FACTS, MYTHS, OLD WIVES TALES AND DOWNRIGHT LIES.

Power claims – how to see through them. Performance camshafts. Acceleration times and maximum speed. More fuel, boost and power. The low down on chip tuning. ECU repairs and dubious checking methods. Aftermarket catalysts. Bogus economy and performance enhancers. Big talking Walter Mitty the engine designer.

Appendix 1. GLOSSARY OF TERMS.

12 pages explaining technical terms, buzzwords etc.

Appendix 2. ON-BOARD DIAGNOSTICS.

The story of the important diagnostic standards OBD1 & OBD2 devised by the California Air Resources Board and now accepted World-wide.

Appendix 3. THE AJ6 IGNITION & INJECTION TESTER.

An established and easy to use instrument that can fire coils, injectors, etc. and detect pickup trigger signals.

Appendix 4. BASIC TESTS WITH A MULTIMETER.

Using an inexpensive multimeter to check through a system.

Appendix 5. THE LABORATORY OSCILLOSCOPE – AN INEXPENSIVE AND VERSATILE INSTRUMENT.

Introduction to the conventional laboratory oscilloscope. How to use this very useful instrument to look at what happens in an automotive system.