Skip the auto shop - Our mechanics make house calls

Q: Idle air valve calibration/adjustment

asked by on

Hi! Recently I managed to clean the lean error code by replacing the intake gasket(upper) and the throttle body gasket as well. No more code to address now, except that I think I need to calibrate my idle air valve duty or counts. Perhaps the previous owner might had messed up with the bypass screw on top of the throttle body due to the lean condition perhaps. Is there a way I can adjust it again without using a bidirectional scan tool? At least to hit 50% or so duty cycle. Our Mitsu dealer MUT tool is not working. Thanks
My car has an automatic transmission.

A: Hi there. It is suggested to have a bidirec...

Hi there. It is suggested to have a bidirectional scan tool but it is not required. Verify the idle speed is within 650-750 rpm. You want to be at 700 rpm ideally. Connect data link connector terminals TEN & GND by using a jumper wire. Adjust the idle speed by turning the air adjusting screw until smooth running anywhere between 500-800 rpm. Disconnect the jumper wire and recheck the RPM’s on the meter. If you need further help adjusting your idle, a qualified professional from YourMechanic can come to your car’s location to pinpoint the proper repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Front tire locking up

A locking front wheel can be catastrophic in many cases. Your vehicle may be experiencing failure in its ABS system. Also this can be a result of a ceased brake caliper. I would have a certified mechanic take a closer...

Q: Flashing check engine light - 2007 Ford Edge

When a Ford vehicle displays a flashing Check Engine Light on the dashboard, this is an indication that your engine has a misfire. I would first recommend having your vehicle scanned for trouble codes with an OBD-2 scanner. This will...

Q: Unknown oil leak in a 2004 Mitsubishi Galant

It can be difficult to determine which fluid is leaking as transmission oil and engine oil eventually turn black if they have not been serviced. Power steering fluid is another common fluid leak most cars experience. A technician must first...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...