What Happens If The Idle Air Control Valve Is Stuck Open? Will IAC Cause A Misfire?

The idle air control valve is a crucial component of our car which can lead to many problems if disrupted. A common interruption in the IAC valve occurs when it is stuck open, especially while cleaning the valve.

Now you may wonder, what happens if the idle air control valve is stuck open?

If the idle air control valve is stuck open, the engine starts idling roughly. Over time, this would make the engine jerky, resulting in it stalling. Note that this would decrease the fuel economy of your car too.

So, this gives you a direct answer to your query. However, you need to read along to unwrap all the details about it with many insights!

Keep on reading till the last of our article.

What Will Happen If the Idle Air Control Valve Is Open?

If you accidentally keep the idle air control valve open on your car, you have to go through a few consequences.

Of course, they are not going to be favorable to your car but adverse. So, take a look at the consequence that you may go through.

1: Rough Idling

The main thing that would result due to this IAC valve being open is rough idling. This would happen as the engine will start idling at comparatively a higher RPM over time.

That means as the idle air control valve is stuck, the engine has complications with idling at the usual RPM. 

So, because of this, the car has to give more pressure to the RPM, which increases its rate. As a result, the engine starts idling rough in a short time.

2: Engine Stalling

When the engine is idling rough, there could be additional consequences. Primarily, the engine may not leave any noticeable effects for this.

However, you would slowly start seeing the effects of the engine idling rough. In a very short time, your car would start giving sudden shakes in the middle of the journey.

Although these might be sudden and not that often, these would still have significant effects on the engine. Over a short period of time, your car would start stalling.

That is the time when you understand that you need to look at the problem and fix it in no time.

3: Decrease in the Fuel Economy

As time passes, you will start getting more symptoms and notice the effects. One of that would be a decrease in the economy of your car fuel.

When your car engine idles rough or stalls, the engine gets to be more worked up. So, they start consuming more fuel from the tank.

As a result of this, the fuel economy of your car decreases. Note that this starts dropping with time and gets quite noticeable over time.

So, these are mainly the consequences that you may face if the idle air control valve of your car is stuck open. Note that you may go through a few consequences other too.

Are There Any Possibilities for the Idle Air Control to Misfire?

You have already come up across the previous segment where you understood what happens if the idle air control valve is stuck open. 

Now, you may be wondering about a common thing, does idle air control misfire anytime? Well, it can, unfortunately! The idle air control valve, alternatively known as the IAC valve, balances the air intake.

With its help, the engine uses the air with fuel and maintains the air to the fuel ratio. Now, if the IAC valve is stuck open, there would be an imbalance in the airflow.

Therefore, there might be more intake of air at times and the other way around the other time. However, it will be prone to take more air for this usually.

Now, there would be chances for the air to react, and the vigorous reaction of oxygen leads to fire. 

So, if oxygen starts reacting, then there would be a misfire at any time. Note that there might be dirt intake for this too. That is why the idle air control valve may misfire if it is stuck open. 

How Do I Reset the Idle Air Control Valve?

Knowing how to reset the idle air control valve is really important. Although it is very easy, people still make mistakes.

Remember that you may need to reset it often, especially when it is stuck open or malfunctioning for the time being. So, take a look at how to reset the idle air control valve.

Step 1: Turn on the Car

First, you need to turn on the car and put the car on ignite mode. That means you do not have to change the gear but keep it in parking mode.

As you turn on your car, press the brake down.

Step 2: Press the Gas Pedal

This time, you have to work with the gas pedal. Put one of your legs on the gas pedal and press it down very slowly.

Then you will have to release the pedal again.

Step 3: Turn off and Restart the Engine

As you release the pedal, you need to keep the car on the ignition for about a few seconds. That means you can not stop the car engine now.

You may keep it like that for about a minute. Then turn off the car and turn it back on again after a minute, and this will fix the issue.

So, this is how you can reset the idle air control valve of your car.

What Are the Symptoms of a Malfunctioning IAC Valve?

You will get early symptoms if your car’s IAC valve is having issues. If you are lucky enough to address and get on them, you could prevent further damage. So, here we have got the symptoms of a malfunctioning idle air control valve.

• The first thing you would see is the Check Engine light on the dash of your car. Note that it may blink or stay lit for a period of time.
• You would notice inefficient or poor acceleration.
• The car may give sudden shakes in the middle of the journey. Note that it could also result in light stalling too.
• Your car might start idling rough at any time. There would be an increase in the idle RPM. 
• You would notice a fluctuation and imbalance in the idle speed of your car.

So, these are the symptoms of a malfunctioning idle air control valve of a car.

How Do I Inspect My Car Idle Air Control Valve?

It is common for the idle air control valve to get damaged. However, if you still want to make sure whether the IAC valve is actually alright or not, you can inspect it by following our steps.

Step 1: Reset the Multimeter

First, you have to set your multimeter to Ohms. To do it, you can go to the settings and reset the option.

Do not turn off or restart the device once you set this to Ohms.

Step 2: Patch up the Multimeter Lead

Now, you will connect the multimeter leads to the valve terminals. Take one lead to attach it to one end of the valve terminal. 

Do the same thing by taking the other lead of the multimeter and then connecting it to the other terminal. 

Step 3: Inspect the Reading

This time you have to inspect the reading; it will indicate whether the valve is going well. If you see the range of the reading lying between 0 to 0.05, the idle air control valve is fine.

However, anything other than this reading would indicate that the IAC valve of your car is bad. Now, if the valve is not up to the mark, you may call an expert to replace it with a new one.

So, this is how you can inspect the idle air control valve of your car on your own.

How Do I Clean the Idle Air Control Valve of My Car Properly?

Cleaning the idle air control valve is necessary from time to time. However, many people are not well aware of doing this in the right way. So, here we have got the steps of how to clean the IAC valve of the car.

Step 1: Locate the IAC Valve

First, you observe where the IAC valve is located. This is placed on the intake manifold around the throttle body. Now, loosen the screws of the intake hose.

After that, unclip and take off the intake hose from the throttle body.

Step 2: Remove the IAC Valve

In this step, you have to disconnect the battery. To do it, dispatch the cable that is on the negative terminal. Then take off the screws from the place of the valve.

As you do this, you now disconnect the electrical plug. After that, take a screwdriver to loosen the clamp and remove all the plugs from the IAC valve.

Step 3: Clean the Valve

Now, take a spray can of carbon cleaner to clean the valve thoroughly. Make sure you clean the valve passages too. 

Keep a piece of dry clean cloth to wipe off any remaining while cleaning the valve. Once you clean it, reconnect the valve to finish off the process.

So, this is how you can clean the idle air control valve of your car.

Is the Idle Air Control Valve Issues Severe for the Car?

Well, it depends actually! If you figure out the symptoms in the primary stage of the valve issue and proceed with the fix, then there might not be any severe problems. 

Plus, if you even fix the issues at the intermediate period, your car still may not have many complications either. But, if you are late to look at those issues, your car engine may have severe disruptions.

Note that it can even have long-term adverse effects on your engine. So, you have to make sure you do not overlook this IAC valve issue at any time.

Frequently Asked Questions

The Final Words

Now you have the answer to what happens if the idle air control valve is stuck open! We believe you can now fix this issue without any complications.

So, before we wrap up, we would like to share the last tip. If you have already fixed the issues of your IAC valve, and you see the engine stalling, hold on. The engine might be having its own complications, which need an expert to look at.