Acura NSX 1997 Service Manual page 263

Main Menu
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 evaporative emission (EVAP) control canister
port are located on the top of the throttle body.
IDLE ADJUSTING
SCREW
TP
SENSOR
Table of Contents
THROTTLE VALVE
CONTROL MOTOR
THROTTLE
VALVE
Inspection
CAUTION: Do not adjust the throttle stop screw. It is
preset at the factory.
1. Start the engine. Hold the engine at 3,000 rpm with
no load (A/T in or
the radiator fan comes on, then let it idle.
2. Disconnect the vacuum hose (to the EVAP control
canister) from the top of the throttle body; connect
a vacuum gauge to the throttle body.
VACUUM PUMP/GAUGE, 0-30 in.Hg
A973X - 041 - XXXXX
3. Allow the engine to idle, and check that the gauge
indicates no vacuum.
If there is vacuum, check the throttle cable (see
page 11-150).
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.
position, M/T in neutral) until
(cont'd)