On Vehicle Inspection

THROTTLE BODY ON-VEHICLE INSPECTION

1. INSPECT THROTTLE BODY





(a) Check that the throttle linkage moves smoothly.





(b) Check the vacuum at each port.
- Start the engine.





- Check the vacuum with your finger.
2. INSPECT THROTTLE POSITION SENSOR
(a) Disconnect the throttle position sensor connector.





(b) Disconnect the throttle opener vacuum hose from the throttle body.
(c) Apply vacuum to the throttle opener.
(d) Insert a feeler gauge between the throttle stop screw and stop lever.

Ohmmeter Connection:

Reference:

(e) Using an ohmmeter, measure the resistance between each terminal.
(f) Reconnect the throttle position sensor connector.
(g) Reconnect the throttle opener vacuum hose to the throttle body.
3. INSPECT AND ADJUST DASHPOT
A. Warm up engine
Allow the engine to warm up to normal operating temperature.
B. Check idle speed

Idle speed: 700 ± 50 rpm
(Transmission in neutral position)

C. Check and adjust dash pot setting speed
(a) Disconnect the control cables from the throttle body.
(b) Push the dashpot push rod all the way with a screw-driver.
(c) Check that the dashpot is set.

Dashpot setting speed:
M/T: 2,600 ± 400 rpm
A/T: 1,800 ± 400 rpm





(d) Adjust the dash pot setting speed by turning the dashpot adjusting screw.
(e) Reconnect the control cables to the throttle body.
D. Check VTV operation
(a) Maintain the engine at 3,500 rpm.
(b) Release the throttle valve and check that the engine returns to idle in a few seconds.
4. INSPECT THROTTLE OPENER
A. Warm up engine
Allow the engine to warm up to normal operating temperature.
B. Check idle speed

Idle speed: 700 ± 50 rpm
(Transmission in neutral position)





C. Check throttle opener setting speed
(a) Disconnect the throttle opener vacuum hose from the throttle body and plug the hose end.
(b) Maintain the engine speed at 2,500 rpm.
(c) Release the throttle valve.
(d) Check that the throttle opener is set.

Throttle opener setting speed: 1,500 ± 400 rpm

If the throttle opener setting speed is not as specified, replace the throttle body.
(e) Reconnect the throttle opener vacuum hose to the throttle body.