1990 HONDA PRELUDE ECU

Air Filter
Replace the air filter every 24 months or 30,000 miles (48,000 km),
whichever comes first (more often in extremely dusty conditions).

Replacement

(2.0 S)
Disconnect the tube, hose and wire connector from the air cleaner
cover.

WING BOLT

CLIP

Loosen the wing bolt and unsnap
the clips,
Remove the old filter and replace it
with a new one, reinstall the cover
and secure it with the clips and wing bolt. Connect the connector, hose
and tube.
(2.0 Si,Si)
Loosen the air filter band.
Loosen the attaching bolts and remove the filter cover and seal. Remove the old filter and replace it with a new one, reinstall the seal
and cover.
Tighten the bolts.
TUBE

CLIP
AIR CLEANER

COVER

CONNECTOR

AIR CLEANER
COVER

HOSE

AIR FILTER

BAND COVER

BOLT

SEAL

AIR FILTERProCarManuals.comMain Menu t s

Changing a Flat Tire (cont'd)
7. Set the jack handle extension in the connector on the end of the jack and install the lug wrench/jack handle. Turn the lug wrench/jack handle clockwise until the tire is slightly off the ground.
8. Remove the lug nuts, wheel cover and wheel.
(Wheel cover is not equipped
with 4WS or ALB models)
9. Install the spare tire; and install the lug nuts hand tight.
10. Lower the car, remove the jack,
then tighten the lug nuts

securely in an "X" pattern as
shown.11. Tighten the lug nuts securely.
The recommended torque is:
110 N .
m(11 kg-m,80 Ib-ft)
If a torque wrench was not

used, ask an authorized Honda

dealer to verify the torque as
soon as possible.
12. Repai
r or replace the damaged tire as soon as you can, then
reinstall it in its original position on the car, and put the spare back
in the car.

CAUTION:

Always stow the jack, tools and tire securely to prevent them
from becoming dangerous projectiles in an accident.
NOTE:
Secure the tire and the spacer as shown in the illustration.
COMPACT SPARE

DAMAGED TIRESPACER
SPACER TIGHTENING TORQUE
110 N.m (11 kg-m, 80 Ib-ft)
VALVE

NUT
WHEEL COVER
LUG WRENCH/JACK HANDLE JACK HANDLE EXTENSIONProCarManuals.comMain Menu t s

Evaporative Emission Control System
The Evaporative Emission Control System is designed to prevent
fuel vapors from escaping into the atmosphere.

(2.0 Si,Si)

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.
(2.0 S)Fuel vapors from the fuel tank and carburetor are directed into the
charcoal canister where they are adsorbed and stored while the
engine is stopped.
When the engine is running and engine coolant temperature is above
the set temperature of the thermo sensor, the purge control diaphragm valve is open so that fuel vapors in the charcoal canister may be drawn into the engine through the carburetor and the intake
manifold.
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. HONDA PGM-FI System (2.0 Si,Si)
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.

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