Throttle Body: Testing and 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 N or P position, M/T in neutral) until the radiator fan comes on, then let it idle.

Throttle Body Inspection:

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.
3. Allow the engine to idle and check that the gauge indicates no vacuum.
^ If there is vacuum, check the throttle cable adjustment, refer to Adjustments.

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.

Throttle Body Shaft Inspection:

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.

NOTE: Replace the throttle body if there is excessive play in the throttle valve shaft or if the shaft is binding or sticking.