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EMISSION CONTROL SYSTEMS
6E-1
SECTION 6 E
EMISSION CONTROL SYSTEMS
CONTENTS OF THIS SECTION
General Description
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6E- 1
Vacuum Hose Schematics
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6E-4
Early Fuel Evaporation System (EFE)
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6E- 14
Exhaust Gas Recirculation System (EGR)
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6E-14
Positive Crankcase Ventilation (PCV)
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6E- 16
Thermostatic Air Cleaner (TAC)
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6E-16
Air Injection Reaction System (AIR)
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6E-18
Engine Performance Specifications
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6E-22
GENERAL DESCRIPTION
The normal operation of the car engine results in the
release of several compounds to the atmosphere. Federal
Government and State of California legislation has placed
limitations on the quantities of three compounds which can
be emitted. The three controlled compounds are:
0
Hydrocarbons
-
HC
0
Carbon Monoxide
-
CO
0
Oxides of Nitrogen-NOX
The Federal regulations for 1977 require that cars sold
for initial licensing, or primary operation in designated high
altitude counties be capable of meeting emission standards at
such altitudes. In most cases, these regulations make it
necessary to have specific engines and emission control
systems for such cars.
The emsission control systems for all engines include:
Carburetor Calibration
Distributor Calibration
Catalytic Converter
Early Fuel Evaporation (EFE) (Except on L4-140)
Exhaust Gas Recirculation (EGR)
Positive Crankcase Ventilation (PCV)
Choke Calibration
Thermostatic Air Cleaner (TAC)
Evaporative Emission Control (EEC)
The emission control system for some engines may use
an additional emission control device called Air Injection
Reaction (AIR).
GENERAL DESCRIPTION
EMISSION CONTROL
COMPONENTS
CARBURETOR CALIBRATION
While the carburetor's main function is to provide the
engine with a combustible air/fuel mixture, the carburetor
calibration is critical to maintaining proper emission levels.
The carburetor's idle, off-idle, main metering, power
enrichment, and accelerating pump systems are calibrated to
provide the best possible combination of engine performance,
fuel economy and exhaust emission control. Carburetor
adjustments and service must be performed using the
recommended procedures to insure engine exhaust emission
levels remain within legislated limits. See Section 6C, Fuel
System, for carburetor adjustment specifications and
recommended service procedures.
DISTRIBUTOR CALIBRATION
The distributor is an integral part of the engine ignition
system and the distributor calibration is an important part
of exhaust emission control. The initial timing, centrifugal
advance and vacuum advance are calibrated to provide the
best engine performance and fuel economy at varying speeds
and loads while remaining within exhaust emission limits.
Distributor diagnostics and service procedures are in Section
6D, Engine Electrical.
CATALYTIC CONVERTER
The catalytic converter is an emission control device
added to the exhaust system to reduce hydrocarbon and
carbon monoxide pollutants from the exhaust gas stream. The
converter contains material which is coated with a catalytic
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