Evaporative Emission Control System; Engine Exhaust Emission Controls; Honda Pgm-Fi System; Catalytic Converter - Honda 1991 Civic Reference Owner's Manual

Hatchback/sedan
Hide thumbs Also See for 1991 Civic:
Table of Contents

Advertisement

Evaporative Emission Control System

The Evaporative Emission Control System is designed to prevent
fuel vapors from escaping into the atmosphere.
Fuel vapors from the fuel tank are directed into the charcoal
canister where they are adsorbed and stored while the engine is
stopped or idling. When the coolant temperature rises to a certain
value, the vapors are drawn into the engine through the throttle
body and the intake manifold during normal engine operation.

Engine Exhaust Emission 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.

HONDA 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 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

Three Way Catalyst
The catalyst is used to convert hydrocarbons (HC), carbon
monoxide (CO) and oxides of nitrogen (NOx) in the exhaust gas,
to carbon dioxide (CO
Exhaust Gas Recirculation (EGR)
(California automatic models except EX Sedan)
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.
), dinitrogen (N
) and water vapor.
2
2

Advertisement

Table of Contents
loading

Table of Contents