Throttle Body: Testing and Inspection

1. Start engine and allow cooling fan to cycle on and off at least once.
2. Connect suitable timing light, then disconnect coolant temperature sensor and set basic timing.
3. Stop engine and reconnect coolant temperature sensor, then disconnect PCV valve hose from intake manifold nipple.
4. Connect tool No. C-5004 or equivalent to intake manifold [1][2]PCV nipple.
5. Connect diagnostic readout box C-4805, then start engine and allow to idle for at least one minute.
6. Using readout box, place read/hold switch in Read position and depress ATM button until code 70 appears.
7. Place read/hold switch to Hold position, then the following should occur:
a. AIS motor will fully close.
b. Spark stabilization will be inhibited.
c. Engine RPM will be displayed on diagnostic readout box in units of RPM x 10. For example, display 95 equals 95 x 10 which indicates 950 RPM.
8. Check idle RPM. If idle RPM is within 850 - 1050, then throttle body minimum air flow is satisfactory. If idle RPM is not as specified, replace throttle body.
9. Shut off engine and remove tools.