On Vehicle Inspection

INSPECTION

Throttle Body Inspection

1. Check that the throttle linkage moves smoothly.





2. Start the engine and check for vacuum with your finger.

Port P: no vacuum at idle, vacuum off idle.
Port E: no vacuum at idle, vacuum off idle.
Port R: no vacuum at idle, vacuum off idle.

Throttle Position Sensor Inspection

1. Apply vacuum to the Throttle Opener.
2. Disconnect the sensor connector.





3. Insert a thickness gauge between the throttle stop screw and stop lever.





4. Using an ohmmeter measure the resistance between each terminal.

Clearance between Between Resistance
lever and stop screw terminals

0 mm (0 in) VTA1 - E2 0.34 - 6.3 k ohms
0.40 mm (0.016 in) IDL1 - E2 0.5 k ohms or less
0.60 mm (0.024 in) IDL1 - E2 Infinity
Wide open throttle VTA1 - E2 2.4 - 11.2 k ohms
Always VC - E2 3.1 - 7.2 k ohms

5. Reconnect the sensor connector and vacuum hose to the Throttle Opener.

Dashpot Inspection

1. Allow the engine to warm up to normal operating temperature.
2. Check idle speed.

Idle speed: 700 ± 50 rpm

3. Check and adjust the Dashpot setting speed.
- Push the Dashpot rod all the way with a screwdriver and verify Dashpot setting.

Speed: 1,800 ± 50 rpm





- If not as specified, adjust with the Dashpot adjusting screw.
4. Check the Vacuum Transfer Valve in the Daspot.
- Maintain the engine at 3,500 rpm.





- Release the throttle and verify that the engine returns to idle in a few seconds.

Throttle Opener Inspection

1. Disconnect the vacuum hose from the Throttle Opener, and plug the hose end.
2. Check the throttle opener setting speed.

Throttle opener setting speed: 1,500 ± 400 rpm

If the Throttle Opener setting is not as specified, replace the throttle body.
3. Turn the engine OFF.





4. Reconnect the vacuum hose to the throttle opener.
5. Start the engine and check that the idle speed returns to the correct speed.

Idle speed: 700 ± 50 rpm