You will need
  • Multimeter. In the absence of an ammeter, and an ohmmeter.
Typically, the system power control with a separate control unit idle speed. Valve idle speed may have the adjusting screw. The location of the control unit the idle speed adjusting screw and the valveand look in a repair manual specific car. New model latest car model years are not equipped with adjusting valveand idle speed.
Before testing two-wire valveand idle speed to warm up the engine to operating temperature (60 degrees), turn off all electrical equipment, ensure good sensor the throttle position, oxygen sensor, leaks in the exhaust system and vacuum system, proper connection of the tachometer.
Start the engine. Serviceable valve idle speed should run continuously (vibrating and slightly buzzing). Then disconnect the electrical connector from the valve. The revs should increase to 2000 rpm.
If the idle speed has not changed, take an ohmmeter and measure the resistance between the contacts of the check valve. This value should range from 9 to 10 Ohms. Make sure that when applying voltage from the battery to the valve it is in a tightly closed state, and when removing the voltage opens. If valve idle speed does not have correct resistance or is not running properly, therefore, it is faulty and must be replaced.
Check current control as follows. Unplugging the electrical connector from valveand connect one pin of the connector with a contact valveand a jumper, and the other through the ammeter (range of the instrument must be 0-1000 mA). When the engine is at idle the ammeter should show a current of 400-500 mA. Any other reading of the ammeter indicates the required adjustment valveand idle speed. Remember, the ammeter may show a current over 500 mA if not fulfilled at least one condition as described in claim 2.
If the ammeter shows no current control, control unit idle speed should be taken to repair or replace a new one. By the way, the reason for the failure of this block may lie in a faulty electrical connector. In this case, please replace the connector.
If the car is equipped with a 3-wire valveohms idle speed, to check follow the same steps described in claim 1 to 4 except for the following details. Electrical resistance measure between the two extreme contacts. It should be 40 Ohms. Then measure the resistance between the Central and outer contacts. It should be 20 Ohms.
Check current control three-wire valveis checked by measuring the voltage at the Central contact. It must match the battery voltage. Between the Central and outer contacts, the voltage should be 10 V.