ignition HONDA PRELUDE 1990 Owner's Manual

Emission Controls (cont'd)
Intake Air Temperature Control System (2.0 S)The air control valve mounted inside the air cleaner snorkel
automatically opens and closes according to the intake air
temperature. The carburetor then receives air of constant
temperature which results in lower exhaust emissions.
Carburetor Controls (2.0 S)—Throttle controller — This system controls the throttle during
gear shifting, reducing the amount of HC caused by unburned

fuel mixture.

— Choke opener — When starting a cold engine, this device
opens the choke slightly. This reduces the amount of HC and

CO.

— Altitude Compensation devices — The Air Jet Controller (AJC)
has an atmospheric pressure sensing bellows. The AJC is
designed to control the amount of additional air fed to the
carburetor jets to maintain good driveability at any altitude. Ignition Timing Control System
This system automatically controls the ignition timing to reduce

the amount of HC and NOx.

Exhaust Gas Recirculation (EGR) [Except California 2.0 S models]
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.
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.
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Catalytic Converter
A catalytic converter is installed in the exhaust system to help
clean-up the 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 55.

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 119.
— 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 Check Engine warning light comes on; have It checked byyour Honda dealer. CATALYTIC CONVERTERProCarManuals.comMain Menu t s

Index (cont'd)

Emission Controls.........................130

Engine
Coolant.......................................88
Coolant Temperature
Gauge....................................20
Identification Number .............127
Oil and Filter...............................83
Oil Pressure
Warning

Light .......................................22

Specification ...........................125

Exhaust Controls....................131
Engine Exhaust Ga
s Warning

....................................................64

Evaporative Emission Control
System ....................................131
Exhaust Gas Recirculation...........132
Exterior Care.................................110
Filters

Air...........................................94
Engine Oil ...................................84

Fuel.............................................96

Fluid .....................................See "Oil"

Foreign Countries, Operation in ...............................56
Four Wheel Steering.......................59 Front Seat
Adjustment..................................5

Fuel

Filter Door and Cap...................56
Fuel Reserve
Warning

Light .......................................22

Gauge.........................................20

Gasohol......................................55

Gasoline ......................................55

Requirement..............................55

Filter...........................................96
Fuse

Checking and Replacing .........101

Specification...........................126 Gasoline............................See"Fuel"
Gas Station Information
...........................................back cover

Gauges............................................20
Glove Box ........................................39
Hazard Warning

Indicator Light ...........................21
Hazard Warning System................33

Headlights

Flasher.......................................31
Headlight Motor
Switch ...........32

High Beam Indicator..................21
High Beam/Low

Beam

Switch...................................31
If the

Retractable Headlights
do not operate ...................123

Reminder Chime

.......................30

Retractable Headlight Motor Warning Light .......................25

Switch.......................................30
Headlight High
Beam Indicator

Light ...........................................21

Head Restraints.................................8

Heating.............................................45

High Bea
m

Switch .......................................31
Indicator Light ...........................21

Hood Latch.....................................39
Identification Numbers.................127
Ignition
Keys.............................................3

Switch........................................58

Indicator Lights ...............................20
Inflation Pressures, Tire..............105
Instrument Panel....................19
Instrument Panel
Brightness

Control.......................................33

Interior light .....................................33
Interior Trim Care .........................110 Jack .............................................116
Jump Starting ...............................119ProCarManuals.comMain Menu t s

Keys
Door Locks ..................................3
Glove box ..................................39
Trunk Lid Lock ............................4
Ignition ........................................58

Key Reminder Beeper...............58Keys.............................................3
Lap/Shoulder Belts
................................Se
e "Seat Belts"

Light

Bulb Replacement...................103
Fuse Replacement ..................101
Light Reminder
Chime ..............30

Operation.................................30

Warning and Indicator Light
......................................................21
Locks

Fuel Filler Door ..........................56
Doors..........................................3

Glove Bo
x ..................................39

Trunk Lid......................................4

Anti-theft Steering

Column

Lock.......................................58

Lumbar Support,Driver's .................7
Maintenace Schedule
and

Records......................................76

Manual Transmission Maximum Allowable Speeds
....................................................66

Oil........................................86
Recommended Shift
Speeds

....................................................66

Shifting.....................................65

Meters Gauges.......See
"Gauges"
Mirrors Power Mirrors ...........................29
Rear View Mirrors ....................29 Numbers, Identification................ 127

Octane Rating,
Gasoline

.......................................... See "Fuel"
Odometer ........................................20Oil

Engine Oil ...................................83

Fluid Locations ..........................82Transmission Oil/Fluid ..............86Oil Pressure Warning Light.......22
Power Steering Fluid ................97
Operation In
Foreign Countries

..........................................................56

Panel Brightness Control ...............33
Parking Brake.................................
39

Power

Mirrors .......................................29
Steering .....................................
97

Windows................................40

PGM-FI System............................131
Pressures, Tire Inflation...............105
Preventive Service.......................

112
(cont'd)
Radiator Coolant .............................88

Radio ................................................47

Rear View Mirrors ..........................29
Rear Window Defogger ..................28
Reminder Lights
..........................See "Warning lights"ProCarManuals.comMain Menu t s