An automobile engine’s throttle body is an essential part. It provides the engine with air for operational requirements. However, over time, you can find several causes for this component to fail.
Surprisingly, they don’t fail in use, and these failures arise when cleaning the device. Cleaning the throttle body is a must preventative maintenance procedure for vehicles as it promotes less turbulent air movement and improves engine maneuverability.
Yet, you’ll find instances where the idle air control valve is all out of whack after cleaning throttle bodies. This can impact your car’s idle speed since a computer regulates it via the throttle body motor assembly.
In our guide, you can learn more about cleaning a throttle position sensor or fixing any problems that arise from doing so. By the end, you’ll know enough to ensure you can clean a throttle body and fix any high idling issues that arise when doing so. (Read Coolant Reservoir Full But Car Overheating)
What is the Throttle Body and why is it Important?
A part of the engine that regulates airflow into it is the throttle body. It comprises a valve, or “throttle plate,” that is opened and closed by the accelerator pedal. When the accelerator pedal is pressed, the throttle plate opens, allowing more air to enter the engine. When the accelerator pedal is released, the throttle plate closes, reducing the airflow into the engine.
The throttle body is an important component in the engine because it plays a crucial role in determining the amount of fuel that is delivered to the engine. The fuel-to-air ratio in the engine must be carefully balanced for the engine to run smoothly. If the throttle body is not functioning properly, it can lead to a variety of issues, including high idle.
Causes Of High Idle After Cleaning Your Throttle body
Vacuum Leak
The mass airflow sensor precisely monitors the air volume entering the engine via the throttle body. When the throttle body allows more air through a leak, the computer makes up the difference and will adjust by supplying more fuel.
When you put the car in drive and let it idle for two to three minutes with all the accessories off, it will idle relearn. The data won’t match the airflow as recorded by the ECU because of the excessive air intake, which will cause the Check Engine light to come on.
A lean fuel-air mixture after the vacuum leak causes irregular idling and sluggish performance. For the engine to operate at its best, it should be repaired, since it is inexpensive and simple to do so. A leak can be as simple as a worn gasket, which is a quick and easy fix.
Leaking Intake Hose
The intake manifold of an internal combustion engine receives measured air through air intake pipes. When they are torn or have holes, it might cause excessive idling with air passing over the throttle.
A lean or excessively fuel-rich combustion mixture that could lead to engine stalling or rough idling could result from the leak, or debris entering the air intake hose through gaps or leaks.
If you hear a sucking or whistling sound, the hose leak may suck in the air, and it needs fixing, so no dirt can enter. (Read Why Don’t Cars Have Mud Flaps Anymore)
Throttle Bore Debris
The plate moves unevenly because of debris in the throttle bore, which also results in rough idling, sluggish or jumpy acceleration, stalling, and poor fuel efficiency.
It also produces:
Grime buildup
It inhibits the car from obtaining enough fuel, causing an imbalance in the flow by obstructing the flow of both air and fuel.
Electrical problems
They may cause the car’s computer to receive sporadic or inaccurate information, which would lead it to incorrectly fix the air-fuel ratio. In addition, it may cause a “limp-home mode switch,” which would give the car’s engine less power no matter how hard you push the pedal.
Computer readjusting
Cleaning the throttle body physically resets the system, requiring the computer in your car to readjust, adding extra fuel to the system, and raising the idle.
How To Fix High Idle Speed After Cleaning Throttle Body
1. Help computer relearn:
You should know you will have a high idle until the car computer relearns it. When you put the vehicle in drive and let the idle for two to three minutes with all the electrical accessories off, the computer relearns the idle. The adaptive system can learn the way we drive and change the settings accordingly.
Turn on your car air conditioner with the fan set in the high position for three minutes after it relearns the idle and the engine runs at the correct operating temperature.
2. Remove and clean your throttle body
When there is debris in the throttle body and it affects the idle air control valve, you can fix this by cleaning the bore’s front and rear. After cleaning, the computer should locate the throttle plate and adjust the idle after some time on the road.
If the problem persists, cleaning may have damaged the throttle sensor, throttle valve, or the motor location. When the throttle plate is opened and closed quickly, this can happen. It needs recalibration and will need a certified mechanic inspection.
3. Using a computer scan tool
It is used to monitor the cars throttle position sensor inputs to see what’s happening. It examines throttle movement and position to find the damage and replacements required to address the serious idling problem.
4. Check the throttle cable
Establish the rest position for the throttle body valve.
5. Check the vacuum hose
Make that there are no leaks in the vacuum hose that connects to the throttle body.
6. Fix the idle air screw atop the throttle body
Fix the idle air screw on top of the throttle body with a flat-bladed screwdriver. When screwed in, the idle speed is decreased; when screwed out, the speed is increased. Adjust until you get normal idle.
Key Throttle Body Problems
- Grime accumulates: When grime and dirt accumulate inside a component, your engine’s performance suffers. The engine’s performance is also impacted by this.
- Poor fuel economy: You must pay more for fuel. Such a situation is brought on by a sharp decline in the average miles per gallon. Your throttle body may be clogged if the average miles per gallon differs from the target value by 10 to 15%.
- Erratic Acceleration: The car speeds up more slowly than normal or in quick bursts.
- Poor or high idling: This can cause the car to stall and increase startup time, but it also saves fuel. The engine consumes additional fuel when the idle speed is high. Starting up is simple, but stalling is more difficult.
- Electrical issue: If the throttle body’s sensor is caked in mud or dirt, it will transmit false information. Modern cars with many electrical features place the car into a secondary power-reduced mode until the problem is fixed correctly.
- Airflow disruptions: Because of the uneven airflow, there will be pressure issues. The car’s performance will gradually deteriorate.
If the throttle body operates poorly, the electronic throttle control will signal a warning. The dashboard’s “check engine light” will glow.
A tube with a pivot and a flat valve serves as a throttle body. It is used to control how much air gets into the engine. The computer receives data from two sensors, the throttle position sensor, and the airflow sensor, and uses it to determine how much fuel should be delivered to the engine’s injectors. (Learn How To Clean Brakes Without Taking Tires Off)
Do I Need To Fix Problems After Cleaning Throttle Body?
Most of the time, after a few days of cleaning, high idle resolves itself spontaneously, and turning the car on and off over a couple of days could reset everything and fix the problem.
If the problem persists, though, you might have messed up when cleaning the throttle body. For a thorough inspection and repair, take the car to a nearby technician.
- After cleaning the throttle body, reset the ECU. Resetting can be caused by several factors, but the main one is “high idle.”
- Without resetting the ECU, the car will speed way too quickly and, if the driver lacks experience, could lose control.
- At idle speed, the rpm will be very high and noisy.
- The car will get harder to stop as well.
Therefore, it’s crucial to reset the ECU after cleaning the throttle body to fix high idle.
How To Relearn An Electronic Throttle Body?
- After you fully release the accelerator pedal, turn on the ignition switch but wait at least two seconds before starting the engine.
- Wait 10 seconds with the ignition switch off and repeat the procedure once more.
- Wait for three seconds with the ignition switch on, then fully depress and release the accelerator five times in quick succession.
- Next, fully depress and hold the accelerator pedal for 20 seconds while fully depressing the brake. You should see the check engine light stop blinking and stay illuminated.
- Fully release the accelerator pedal within three seconds.
- Start the engine and let it run at idle for 20 seconds.
- Give it a couple of quick revs to see if the idle speed falls into an acceptable range.
- The vehicle should be started and left idling in park for three minutes.
- The rpm will be high but will drop as the ECU learns new idle cells.
- Switch off the ignition for 60 seconds, then restart while in park for three more minutes.
- Now, your engine should idle as normal after three minutes.
Tip: Some reports claim disconnecting the battery induces the fix.
FAQs
Can you use WD40 to clean the throttle body?
WD40 is ineffective as a throttle body cleaner. The throttle body will have substantial deposits adhered to it, and the throttle plate will require a throttle body solvent.
To remove carbon and other deposits from the throttle body caused by fuel, there are throttle body cleaners or carb cleaners that can break down these deposits.
Can a bad throttle body cause a car not to start?
It’s possible that driving with a damaged throttle body won’t instantly impact the car’s engine. Long-term use of a damaged throttle body, however, can make the car misfire.
Often, there will be high idle or low idle as well. Hence, it is advised to visit a mechanic as soon as possible for further inspections.
Is It Expensive To Fix A Throttle Body?
Throttle body cost ranges from $370 to $1500. $70-$260 for labor. Parts cost $110 to $600, so the average price will be around $587.
The throttle body controls airflow in today’s engine. It can cause automotive problems for many reasons. You can quickly spot these engine problems.
The reasons it can go bad are:
- Carbon buildup in the housing
- Rough idle after cleaning the throttle body
- Electrical problems
- Vacuum Leaks
How often do you replace the throttle body?
The lifespan of a throttle body has no predetermined mileage. But after 45,000 miles, you need to give it a thorough cleaning. The car will run more efficiently and have a longer lifespan after cleaning. (Learn How To Clean Aluminum Intake Manifolds)
The throttle body is an essential part of an automobile’s engine, and using the right techniques, you can clean it with a throttle body cleaner to resolve issues.
