Auxiliary Air Valve (Idle Speed): Testing and Inspection

Fig. 5 Auxiliary air valve testing:

Checking can only be done with engine cold.
1. Isolate safety circuit by disconnecting terminal on air flow sensor.
2. If cold engine control pressure is to be checked, the terminals on warm-up regulator should be disconnected to prevent the bi-metal strip from warming up.
3. Check opening using method in Fig. 5.
4. Switch on ignition. Opening should close after 5 minutes.
5. Check power supply if valve does not close.
6. If voltage is available, measure the resistance of the heating coil. The resistance measured should be 40 Ohms. Replace valve if no electrical fault is found.