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.

Inspection
CAUTION: Do not adjust the throttle stop screw. It is preset at the factory.

1. Start the engine and allow it to reach normaloperating 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.

3. Allow the engine to idle and check that the gauge
indicates no vacuum.
•   If there is vacuum, check the throttle cable (page 11-123).
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.