ignition HONDA CIVIC 1991 Owner's Manual

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 throttlebody 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 moreaccurate 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 2
), dinitrogen (N 2
) and water vapor.

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.ProCarManuals.comMain Menu s t

Catalytic Converter

A catalytic converter is installed in the exhaust system to help
clean-up the harmful exhaust gases that can cause air pollution.
To be effective, the converter must work at high temperature, so don't park your car over dry grass, leaves or anything else that

could burn easily.

To stay effective, the converter must not be contaminated by

leaded gasoline; use only unleaded gas as explained on page 54.

CAUTION:
The converter can be overheated and damaged if it's fed too much
unburned fuel mixture from the engine, so:
— Don't push or tow the car to start it; if the battery is dead, jump start the car as shown on page 110.
— Don't turn the key off while the engine is running above idle
speed.

— Don't change the ignition timing, or remove any emission control
parts.

— Use only the spark plugs specified in this manual. — Don't keep driving your car if it isn't running properly, or if its CHARGE warning light comes on; have it checked by your
Honda dealer.
CATALYTIC CONVERTERProCarManuals.comMain Menu s t

Index (cont'd)

Specification (Sedan)............ 119
Engine Exhaust Gas Warning........ 60
Evaporative Emission Control
System.................................... 125

Exterior Care.................................. 99
Filters

Air.............................................. 86
Engine Oil.................................. 76

Fuel........................................... .86

Fluid..................................... See "Oil"
Foreign Countries, Operation in.... 55
Front Seat
Adjustment................................. 6

Fuel
Filler Door and Cap................... 55
Fitter..........................................86
Gasohol..................................... 54

Gasoline .................................... 54

Gauge........................................ 28

Requirement............................. 54

Fuse
Checking and Replacing .......... 91Specification (Hatchback).... 116
Specification (Sedan)............ 119

Hatch................................................. 5

Hatch/Trunk-open Indicator Light
...................................................31

Hazard Warning System............... 37

Headlights
Flasher...................................... 36
High Beam Indicator................. 29High Beam/Low Beam Switch ...............................................36

Switch...................................... 36

Headlight High Beam Indicator Light
...................................................29

Head Restraints................................ 7
Heating............................................. 50 High Beam
Indicator Light.......................... 29

Switch...................................... 36

Hood Latch..................................... 41
Identification Numbers................ 121
Ignition Keys............................................ 3

Switch....................................... 57

Indicator Lights.............................. 29
Inflation Pressures, Tire................ 94 Instrument Panel............................ 26
Instrument Panel Brightness Control ................................................... 37

Interior Light................................... 37

Interior Trim Care .......................... 99
Keys
Door Locks................................. 3
Hatch/Trunk Lid Lock................ 5

Ignition....................................... 57
Keys............................................ 3
Lap/Shoulder Belts .......................... See "Seat Belts"
Light Bulb Replacement.................... 92
Fuse Replacement................... 90
Operation.................................. 36
Warning and Indicator Lights.. 29
Locks
Anti-theft Steering Column Lock...............................................57
Child Proo f
Door Locks ............. 5

Doors........................................... 3

Fuel Filler Door.......................... 55 Hatch/Trunk Lid......................... 5
Power Doors.............................. 4
Luggage Area Light........................ 38
Luggage Cover................................. 9
Gasoline............................ See "Fuel"
Gas Station Information. back cover

Gauges............................................ 28

Glove Box....................................... 42 Jack.............................................. 106
Jump Starting.............................. 110ProCarManuals.comMain Menu s t