nsxe11114a.pdf

Air Intake System
Throttle Body
Description
The throttle body is of the single-barrel side-draft type.
The lower portion of the throttle valve is heated by
engine coolant which is fed from the cylinder head. The
idle adjusting screw which increases/decreases bypass
air and the canister/purge port are located on the top of
the throttle body. A dashpot is used to slow the throttle
as it approaches the closed position.
Inspection
CAUTION: Do not adjust the throttle stop screw since
it preset at the factory.
1. Start the engine and allow it to reach normal
operating temperature (cooling fan comes on).
2. Disconnect the vacuum hose (to the canister) from
the top of the throttle body; connect a vacuum
gauge to the throttle body.
DASHPOT
DIAPHRAGM THROTTLE
STOP SCREW
IDLE ADJUSTING
SCREW
THROTTLE
ANGLE SENSOR
VACUUM PUMP/GAUGE
A973X-041 -XXXXXTHROTTLEVALVE
THROTTLE
ACTUATOR 3. Allow the engine to idle and check that the gauge
indicates no vacuum.
If there is vacuum, check the throttle cable
(page 11-113).
4. Check that vacuum is indicated on the gauge when
the throttle is opened slightly from idle.
If the gauge indicates no vacuum, check the
throttle body port. If the throttle body port is
clogged, clean it with carburetor cleaner.
5. Stop the engine and check that the throttle cable
operates smoothly without binding or sticking.
If there are any abnormalities in the above steps,
check for:
Excessive wear or play in the throttle valve
shaft.
Sticky or binding throttle lever at full close
position.
Clearance between throttle stop screw and
throttle lever at full close position.