Throttle Body - Honda Acura NSX 1991 Service Manual

Air Intake System
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
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.
DIAPHRAGM
THROTTLE
STOP SCREW
I
ACTUATOR
1 l-l 14
increases/decreases bypass
IDLE ADJUSTING
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.
-XXXXX
3. Allow the engine to idle and check that the gauge
indicates no vacuum.
(page 1 l-l 13).
4. Check that vacuum is indicated on the gauge when
the throttle is opened slightly from idle.
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.
check for:
shaft.
position.
throttle lever at full close position.