The first thing you need to know about a faulty throttle body is that it’s function of controlling the engine’s air intake will fail. Air within the engine plays an important role in terms enabling engine power acquisition. The throttle body’s location between the air intake and engine manifold allows for air to stream into the engine for combustion purposes.
This process depends on the gas pedal which is responsible for acceleration. Once you press the accelerator it links to a butterfly valve which controls the amount of fresh air sucked into the engine. Further, the gas pedal works alongside the onboard computer to balance the air taken into the manifold with the fuel ratio. The perfect balance is facilitated by essential sensors within the system.
What causes damage to the throttle body?
Since the throttle body is an air passage way to the manifold, anything that interrupts this may cause the throttle body to fail. The throttle body is damaged due to dirt and carbon suit accumulation, a faulty air filter and a faulty throttle position sensor.
1. Dirt and carbon suit.
The throttle body relates to the engine’s combustion of the air and fuel mixture to offer power. This process of combustion releases gases that have particles of carbon. Further, the air flowing through the throttle body from outside may have particles. These particles may accumulate within the throttle body. Hence causing the butterfly valve to get stuck.
2. Faulty air filter.
If the car’s air filter isn’t performing to the optimum, there will be dirt in the air taken into the engine. These particles within the air will eventually accumulate within the throttle body. Hence blocking the throttle body, a situation known as coking. At this point, the throttle body will need to be cleaned.
3. Faulty throttle body position sensor.
The first thing you will notice when the throttle body sensor is faulty is the check engine light. Depending on the onboard computer’s programing, there are cars that will display a reduced engine power warning.
Well, the throttle body position sensor is responsible for measuring the air and fuel mixture. This sensor is part of the fuel management system. Meaning a faulty throttle position sensor could be one of the reasons why the car consumes more fuel. Because it sends direct signals to the fuel injection system to inform it about the amount of power the engine is demanding.
Further, the throttle position sensor measures how quickly the throttle position changes. This data combines with the mass air flow sensor’s data, air temperature and engine rotations per minute RPM. This data isn’t combined because there is a faulty throttle position sensor.
Signs of a bad throttle body.
After establishing that the throttle is responsible for the engine’s power, an obvious sign could be low engine power. In fact, sings of a bad throttle body will revolve around the engine.
1. Rough idling.
When you start the car, there is the normal vibrations that you get from the engine. If the vehicle is vibrating excessively when its idle, a faulty throttle body may be the issue. Additionally, this could be coming from a faulty spark plug or engine motor mounts. Find out more information about the reasons why the car is shaking here. Rough idling will also be accompanied by sound noises when the throttle body is faulty.
2. Check engine light.
The car’s onboard computer lets you know when something isn’t working well within the vehicle. This is made possible through the various sensors that monitor functionality. There are a number of sensors within the throttle body that connect to the onboard computer. When the throttle body is faulty, these sensors communicate to the onboard computer which displays the check engine light. There are numerous other reasons for the check engine light to appear.
3. Reduced acceleration performance.
As we had mentioned earlier, the throttle body is responsible for regulating the air intake that mixes with fuel. This mixture burns in order to provide sufficient power for the engine’s acceleration. Further, the throttle body takes in air according to the acceleration speed specifically when you press the gas pedal.
Now if the throttle body is faulty, there will be an unbalanced air and fuel mixture. This will affect the ability for the car to accelerate when you press the accelerator. This is likely to be noticed when you’re taking off, you will see that the car takes a lot of time to get to higher speeds.
4. Engine Misfires.
An engine could misfire because of a number of things inclusive of a faulty spark plug and a problematic throttle body. The throttle position sensor is responsible for exchanging data with mass air flow sensor and fuel injector to create a good air and fuel mixture. If something is wrong within this data exchange network, engine misfires are a likely result.
The engine misfires when there is an incomplete combustion of fuel and air mixture. Hence the reason why a faulty spark plug can cause an engine misfire. Because the faulty spark plug will provide a weak spark.
5. Poor engine performance.
Since you are used to driving your vehicle, you already know how it responds when you accelerate. when you drive with a bad throttle body, the acceleration will be down. That’s because a faulty throttle body will be unable to regulate the air and fuel mixture and that will lead to insufficient combustion. If the car feels like it has lost it’s acceleration performance, a faulty throttle body could be the cause of this.
6. Low fuel mileage.
The throttle position sensor sends data to the fuel injector concerning the engine’s power demands. If the engine demands more power, the fuel injector will supply more fuel while the throttle body takes in additional air. If the throttle body is unable to take in more air when there is a demand, the fuel and air mixture will be unbalanced.
This means that the fuel won’t be burnt well and the car will end up using too much fuel. You will observe that the amount of fuel you use for a certain distance will reduce. Additionally, you will start refilling the tank after short distances which is unusual. This calls for an investigation of the throttle body and fuel injectors.
7. Engine dying when idle.
The throttle body flap fails to function properly when there is too much suit or dirt particles on it. This will prevent it from flapping into position when the engine starts. Hence causing low air intake into the engine for fuel combustion. This won’t change despite an installation of the air intake engine modification.
When the engine starts and there isn’t sufficient amounts of air intake the engine RPM will be too low. This will eventually cause the engine to shut down when it’s idle or when you start to drive. Yes, a bad throttle body can cause the car to shut off.
What happens when you drive with a bad throttle body?
First of all, the engine rpm is under great influence from the throttle body. When you’re starting the car, the engine demands a given amount of air in order to keep running. At this point, the throttle flap is slightly open because the car does not demand a lot of power.
When the throttle flap is faulty, it lowers the amount of air going into the engine. This causes an imbalance between the fuel and air mixture within the combustion chamber. Engine RPM reduces as a result of this and the engine may shut down as you drive or when it’s idle. Occasionally the engine RPM will go up when there is a faulty throttle body. Because the throttle body plays a key role in maintaining a steady engine RPM.
Further, you may ignore an engine’s misfire when you first experience it. This problem gets complicated further when it is ignored. I mean that the effects of a faulty throttle body will spread to the other engine systems associating with it’s functionality. That is, the catalytic convertor, oil and vital engine parts could get damaged.
1. Damaged catalytic converter.
The throttle body regulates the flow of air which mixes with fuel in the combustion chamber. Driving with a faulty throttle body will cause the fuel not to burn sufficiently. This will cause the fuel to pass out to the oil or through the exhaust pipe.
In order for it to pass out through the exhaust pipe, it will have to pass through the catalytic converter. This excess fuel will cause damage to the catalytic converter. Because the catalytic converter eliminates toxic gases and pollutants found in the exhaust fumes through a redox reaction. The catalytic convertor isn’t meant to handle the unburnt fuel so it will be damaged.
2. Damaged engine oxygen sensor.
The oxygen sensor is responsible for monitoring the level to which the fuel has burnt. If it is not functioning well, a dashboard warning light will be shown. For most vehicle onboard computers, their programing allows that the check engine warning light is the one that comes up. Further a faulty oxygen sensor leads to excessive exhaust emissions and bad performance. A faulty throttle body may lead to damage of the oxygen sensor due to unbalanced air and fuel mixture ratio.
Damage to the oxygen sensor my occur when the fuel hasn’t been burnt properly and it passes out through the exhaust pipe. The oxygen sensor detects if the fuel burning is rich meaning that oxygen is insufficient in the combustion chamber. Alternatively the fuel burning could be lean meaning that oxygen is present in excess within the combustion chamber.
3. Oil damage.
The excess fuel that results from ineffective combustion due to driving with a faulty throttle body flows into the oil’s reservoir. This causes the oil formula to brake down and makes the oil ineffective in performing its lubrication and cooling purposes.
4. Damage to vital engine parts.
Well the engine’s functionality relies on the effective functionality of system components. In this case, driving with a bad throttle body will extend damage to the other parts of the engine system. When the inefficiently burnt fuel flows into the oil and disrupts its composition it endangers the other engine components.
How do you test the throttle body?
Within the throttle body you will find the throttle position sensor TPS which communicates with the onboard computer. Additionally, the throttle position sensor communicates with the fuel injector to ascertain the amount of fuel that needs to be released for a perfect fuel and air mixture. The TPS also monitors the angle of at which the throttle valve is open when you press the accelerator.
When the throttle position sensor TPS is faulty, the engine usually doesn’t receive sufficient fuel. As a result of this you will notice that the engine will be stalling. But how will you test the throttle body if you suspect that something isn’t right. Lets explore;
1. Locate the throttle body.
It is located over the engine block with a fuel line that leads to its position. There is a device attached to the throttle body and it has wires running into the engine control module. That one is the throttle position sensor TPS.
2. Check the reference voltage.
When the TPS is functioning well the voltage is usually passing to it from the engine control unit. Use a multimeter to test if the voltage is passing. The voltage is usually around 5 volts. Touch the negative probe of the multimeter to the negative wire and the positive probe to the positive wire.
3. Check signal voltage.
Touch the positive probe to the signal wire tab and the ground tab to the frame of the car. You should get a 1/2 voltage reading from the multimeter if the TPS is working well.
Step by step guide to cleaning a throttle body.
Step 1. Disconnect the ground terminal [negative] of the car battery.
Step 2. Mark or label each hose connecting to the throttle body so that you can remember them during restoration. You will have to remove the hoses to access the throttle body.
Step 3. Remove the air ducts connecting to the throttle body so that you can expose the throttle body for cleaning. Be careful not to interfere with the wiring around the throttle position sensor.
Step 4. Afterwards, the throttle body is exposed for cleaning. Spray the throttle body cleaner and use a cloth or a gentle bristle brush to clean out the dirt gently.
Step 5. Apply some general purpose oil onto the throttle shafts where it enters the throttle body. This oil is useful for keeping the throttle flaps rotating smoothly.
Step 6. Reinstall the throttle body ducts and ensure the hoses are tightly held in place. Afterwards, reconnect the battery and close the hood.