Idle Air Control Valve IAC 237810F300 for 1990-04 Nissan D21 Pickup D21 2.4L I4

New Idle Air Control Valve For Nissan D21 Pickup L4-2.4L

1990-1994 D21

1994-2004 Pickup

Know about the Idle Air Control Valve (IAC):

How does the IAC works

An IAC (idle air control) motor is designed to adjust the engine idle RPM speed by opening and closing an air bypass passage inside the throttle body. The cars computer or PCM (powertrain control module) receives information from various sensors and will output signals to adjust the idle air control motor in or out to adjust engine idle speed by controlling engine idle air. An idle air control motor can fail one of two ways, either the motor short circuits and stops working or the motor will develop high resistance and cause the idle air control motor to react slowly, either failure can cause the engine to stall at idle. When a trouble code scan is performed it sometimes won't always detect a failed or weak idle air control motor.

Common Problems:

An idle air control motor is highly susceptible to carbon and coking build up; if an idle air control goes too long without cleaning it can cause stalling and poor idle quality. Some cars are designed with a large vacuum transfer hose that connects the intake manifold to the idle air control motor. If a broken or dilapidated these vacuum lines can cause the engine to lose vacuum which will allow the engine to run rough and die. Inspect all engine and accessory vacuum lines to look for missing, torn or dilapidated lines and replace as needed. Any car that is designed with a magnetic non-motor operated idle air control like Toyota and Lexus is subject to carbon and should be cleaned about every 40,000 miles to avoid stalling.

Cleaning the IAC:

Despite what some will tell you, the Idle Air Control can be cleaned in many cases. It will have to be removed from the engine, but standard carburetor cleaner will often clear out the gunk and allow the pintle to slide freely again. Remove the unit, spray the cleaner into the housing and work a rag into the housing to clear out any remaining dirt and debris. Be sure to wear proper protective eye wear. You may need to let the unit soak in carburetor cleaner for a while.

Replacing the IAC

In most cases the IAC is mounted on the top of the engine in an easy to reach position. It is also usually only held on with two bolts. Simply loosen the bolts to remove the module. There is a plug wire attached to it that allows it to be controlled by the ECM. Unplug this plug. Once the old module is off, simply bolt the new one in it's place, being sure to use the new gasket between the module and the engine. Do not use the old gasket as this can be worn and may allow debris to enter the new module. Once bolted on, plug the wire plug into the new unit and you are finished.