Idle air control valve: common defects and their signs

1. Wear-out of the conical needle guides.
   • Engine RPM increases or lowers unpromptedly.
   • Engine rotation speed doesn’t increase at the cool engine.
   • Idling rpm abruptly decreases at activation of the car electric equipment.
2. Wiring breakage.
   • The engine operation is not stable at idling.
   • The engine doesn’t operate on high rpm after start.
   • “Check engine” indicator activates.

How to repair or replace idle air control valve?

In case of oiling or soiling of the idle air control valve contacts, they can be cleaned with special compounds. It is necessary to clean the mounting seat on the throttle unit, where the conical needle of the valve is housed, together with the control valve itself.

If cleaning of the control valve doesn’t help to restore air supply by-passing to the rotarythrottle, the component should be replaced. Demounting of the car part is performed for cleaning and replacement; any car owner can handle it. Actions sequence may vary for cars of different models, that is why, before starting work, study technical documentation for the vehicle. Generally, in order to replace the part you need to:

1. Disconnect the negative terminal from the battery.
2. Remove the engine protective cover.
3. Loosen the clamp, fastening the air filter pipe and disconnect the corrugated hose.
4. Detach the throttle cable.
5. Unscrew fasteners and demount the throttle unit.
6. Detach fasteners of the idle air control valve and remove it.
7. Install a new component together with a new sealing ring.
8. Perform assembling of the unit in reverse order.