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1、Welcome To,Air Induction System Operation & Diagnosis,SECTION 2,Objectives,Explain the operation of the components in the air induction system. Describe how the engine creates vacuum and how vacuum is used to operate and control many automotive devices. Inspect and troubleshoot vacuum and air induct
2、ion systems.,continued,Objectives,Explain the operation of exhaust system components. Properly perform an exhaust system inspection, and service and replace exhaust system components. Explain the purpose and operation of a turbocharger.,continued,Objectives,Inspect a turbocharger, and describe some
3、common turbocharger problems. Explain supercharger operation, and identify common supercharger problems.,continued,Air Induction System Functions,Air induction systems Silence intake air noise. Heat or cool the intake air. Provide air for the engine to operate. Filter the air. Monitor airflow temper
4、ature and density. Operate the PCV system. Provide air for the air injection system.,continued,Air Induction Components,continued,Intake Manifold Components,A late-model intake manifold for a V-6 engine,continued,Engine Vacuum,It is produced by the downward movement of the piston on the intake strok
5、e. It is pressure that is less than atmospheric pressure. It is usually measured in millimeters of mercury (mm/Hg) or inches of mercury (in/Hg).,continued,Vacuum Problem Diagnosis,Check hoses for improper routing. Look for kinks and tears in vacuum lines. Check for vacuum hoses routed near hot spots
6、. Look for evidence of oil or transmission fluid in vacuum hose connections. Inspect vacuum system components for damage.,continued,Exhaust System Components,Exhaust manifold Exhaust pipe and seal Catalytic converter Muffler Resonator,Tailpipe Heat shields Clamps, brackets, and hangers Exhaust gas o
7、xygen sensors,continued,Exhaust System Components,An exhaust system for an OBD-II vehicle,continued,Exhaust System Inspection Items,Holes, road damage, and split seams Kinks or dents Discoloration or rust Broken or missing hangers Loose tailpipes or other components Signs of catalytic converter over
8、heating: Bluish or brownish converter shell,continued,Common Exhaust Work Tools,continued,Turbocharger Components,Turbine (hot wheel) Turbine shaft Compressor (cold wheel) Waste gate valve Actuator,continued,A Turbocharger Cross Section,continued,Typical Turbocharger System,continued,Turbocharger Pr
9、oblems,Lack of lubricant Is commonly caused by infrequent oil changes or using the wrong oil. Ingestion of foreign objects Contamination of lubricant May be caused by defective seals.,continued,Superchargers,Superchargers are air pumps directly driven by the engines crankshaft by a belt. They improv
10、e horsepower and torque by pumping extra air into the engine in direct relationship to crankshaft speed. This positive connection provides for instant power response.,continued,Superchargers,Many of the problems and their remedies given for turbochargers hold good for superchargers. There are also p
11、roblems associated specifically with the supercharger. Refer to the service manual for the symptoms of supercharger failure and a summary of the causes and the recommended repairs.,continued,Superchargers,Cutaway of a Roots supercharger,Supercharger drive setup,continued,Summary,Most turbochargers a
12、re lubricated by pressurized engine oil. Most turbocharger systems use knock-sensing devices and a waste gate. Superchargers are air pumps connected directly to the crankshaft by the belt.,continued,Summary,The most popular supercharger design is the Roots type. Another supercharger design is the G-Lader supercharger.,
