1990 Honda Accord Owner's Manual - Page 129

1990 Honda Accord Manual

Page 129 highlights

Emission Controls (cont'd) Engine Exhaust Controls The engine exhaust emission control systems are designed to control combustion during idle, acceleration, cruise, and deceleration. These systems are entirely separate from the crankcase and evaporative emission control systems described previously. PGM-FI System The PGM-FI system consists of three independent subsystems; Air Intake, Electronic Control and Fuel Control, thus allowing more accurate control of air/fuel ratios under all operating conditions. The Electronic Control Unit (ECU) detects the amount of air drawn into the cylinders and determines the amount of fuel to be injected to provide the optimum air/fuel ratio for all engine needs. Ignition Timing Control System This system automatically controls the ignition timing to reduce the amount of HC and NOx. Catalytic Converter The catalyst is used to convert hydrocarbons (HC), carbon monoxide (CO) and oxides of nitrogen (NOx) in the exhaust gas, to carbon dioxide (CO 2 ), dinitrogen (N 2 ) and water vapor. Exhaust Gas Recirculation (EGR) The EGR system is designed to control the formation of oxides of nitrogen (NOx) caused when fuel mixture burns at high temperature. It works by recirculating exhaust gas through the EGR valve and intake manifold into the combustion chambers where it reduces peak temperature by diluting the air/fuel mixture.

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Emission Controls (cont'd)
Engine Exhaust Controls
The engine exhaust emission control systems are designed to
control combustion during idle, acceleration, cruise, and decel-
eration.
These systems are entirely separate from the
crankcase and evaporative emission control systems describ-
ed previously.
PGM-FI System
The PGM-FI system consists of three independent sub-
systems; Air Intake, Electronic Control and Fuel Control, thus
allowing more accurate control of air/fuel ratios under all
operating conditions.
The Electronic Control
Unit (ECU)
detects the amount of air drawn into the cylinders and deter-
mines the amount of fuel to be injected to provide the optimum
air/fuel ratio for all engine needs.
Ignition Timing Control System
This system automatically controls the ignition timing to
reduce the amount of HC and NOx.
Catalytic Converter
The catalyst is used to convert hydrocarbons (HC), carbon
monoxide (CO) and oxides of nitrogen (NOx) in the exhaust
gas, to carbon dioxide (CO
2
), dinitrogen (N
2
) and water vapor.
Exhaust Gas Recirculation (EGR)
The EGR system is designed to control the formation of oxides
of nitrogen (NOx) caused when fuel mixture burns at high
temperature. It works by recirculating exhaust gas through the
EGR valve and intake manifold into the combustion chambers
where it reduces peak temperature by diluting the air/fuel
mixture.