Computer Signals 239
Computer System Operation 243
Sensors 244
Computers 249
Actuators 255
Highway History 257
Chapter 18 261
On-Board Diagnostics and Scan Tools
On-Board Diagnostic Systems 261
Scanning Computer Problems 265
Energizing OBD I Systems without a Scan Tool 274
Erasing Trouble Codes 277
Duff’s Garage 278
Chapter 19 282
Computer System Service
Preliminary Visual Inspection 282
Computer System Circuit Problems 283
Sensor and Actuator Problems 284
Sensor Service 285
Actuator Service 288
Computer
Service 291
Duff’s Garage
295
Computer
System
Sensor and
Actuator
Diagnosis
298
Section 4
Fuel Systems
Chapter 20 301
Automotive Fuels, Gasoline and Diesel
Combustion
Petroleum (Crude Oil) 301
Gasoline 301
Diesel Fuel 307
Alternative Fuels 310
Duff’s Garage 312
Chapter 21 315
Fuel Tanks, Pumps, Lines, and Filters
Fuel Supply System 315
Fuel Supply System Service 324
Workplace Skills 335
Fuel Delivery System Diagnosis 339
Chapter 22 340
Gasoline Injection Fundamentals
Gasoline Injection Fundamentals 340
Gasoline Injection Classifications 342
Throttle Body and Multiport Injection 342
Gasoline Injection Controls 344
Electronic Fuel Injection 345
Engine Sensors 348
Injector Pulse Width 354
Throttle Body Injection 355
Engine Idle Speed Control 357
Continuous Throttle Body Injection 358
Electronic Multiport Injection 358
Air-Fuel Emulsion Injector 358
Unitized Multiport Injection 358
Injector Resistor Pack 362
Airflow-Sensing Multiport EFI 362
Pressure-Sensing Multiport EFI 364
Hydraulic-Mechanical Continuous Injection
System 364
Fuel Accumulator 366
Direct Gasoline Injection 366
Industry Trend 367
Chapter 23 371
Gasoline Injection Diagnosis and Repair
Gasoline Injection Problem Diagnosis 371
Fuel Pressure Regulator Service 374
Injector Problems 376
Throttle Body Injector Service 376
Servicing EFI Multiport Injectors 378
Engine Sensor Service 384
Control Module Service 388
Gasoline Injection Adjustments 389
Testing Idle Control Motor 390
Multiport Throttle Body Service 391
Duff’s Garage 391
Gasoline Injection System Diagnosis 392
Chapter 24 396
Carburetor Operation and Service
Basic Carburetor 396
Carburetor Problem Diagnosis 403
Highway History 408
Chapter 25 410
Diesel Injection Fundamentals
Basic Diesel Injection System 410
Diesel Injection System Accessories 422
Piezo Diesel Injectors 424
Accident Report 425
x Expanded Contents