And so, have you been experiencing problems with the acceleration of your car lately? It’s just not accelerating as it used to, and you are asking the question as to why is my car not accelerating. Well, there could be many things that can cause your car not to accelerate, and we are going to cover most of them in this article.
- Why Does This Problem Matter?
- Simple Problems & Causes
- Complex Problems & Reasons
- 1. Ignition Issues
- 2. Sensor Issues
- 3. Engine Problems
- 4. Fuel System Problems
- Final Conclusion
- Frequently Asked Questions (FAQs)
Acceleration is important because there is nothing like a good punchy car boost off the line. Personally, that’s one of the things that put a smile on my face and made me enjoy my car even more. There is nothing else like it. That’s why supercars are one of the hottest commodities on the market – because they deliver thrills.
But enough rambling about supercars. Let’s discuss more on why is my car not accelerating. If your car is not accelerating, it can be caused by many different things. These can be mechanical issues or electrical issues. Or, maybe you just have deflated tires. Anything can ruin your car’s performance.
In this article, we are going to cover all of the reasons why is my car not accelerating. Then we are going to explain how to solve these issues on your own or by visiting a mechanic. It will work either way. So, without further ado, let’s get into the article.
Car Won’t Accelerate
Acceleration is important when you have a vehicle. There are two factors to account for this. Number one is the safety factor, and number two is the fun factor.
If your car is not accelerating well, it can drive you into danger. Imagine that you are passing a slow car on the road and you’re desperately trying to go around it. You move into the left lane and you apply the gas pedal but nothing happens. Suddenly a car appears in the left lane and your life flashes before your eyes.
You need a car that can manage decent acceleration to perform these basic on-road maneuvers. If your car does not accelerate well, it could cause you some difficulties while you’re on the move.
The other aspect is the fun part. You need to have a car that accelerates from a dead stop in a good amount of time. You don’t want a sluggish car that needs 10 or 15 seconds to reach 60 mph. This is not acceptable.
There is nothing enjoyable in driving some poorly accelerating car. If your car used to accelerate better and is not accelerating well anymore, you should ask yourself the question why is my car not accelerating? Then, you have to address this issue.
There can be many things that may cause your car not to accelerate. There are sensor-related issues, mechanical problems, as well as electrical problems. Anything can happen, and we’ve made a list of the most common issues that make a car not accelerate.
These issues are one of the first things you need to pay attention to and try to fix if they are broken. Then we are going to explain how to fix them. So, let’s begin.
Why Won’t My Car Accelerate
If you are asking yourself the question why is my car not accelerating the first thing that comes to your mind is something really scary. You should think twice because some simple problems can cause your car to have poor acceleration. Some of them are really quite simple, actually.
Why Is My Car Not Accelerating, Common Causes #1. Deflated Tires
Deflated tires are usually one of the most common reasons why your car is not accelerating. A deflated tire can ruin your performance by a big margin. This is because your tire shape is not round anymore.
The tire lies now flat on the ground, and this allows the tire to create a lot of traction with the road surface. This extra grip puts a lot of stress on the engine and transmission. Thus, it is making the car slower and harder to move around. That’s why you should always check your tires and the tire pressure.
Go to your local gas station and inflate your tires. After this, your car should drive fine again. And always remember to inflate them every once in a while. They can lose air if they aren’t inflated for a few months.
Why Is My Car Not Accelerating, Common Causes #2. Emergency Brake On
Another blunder is leaving the emergency brake on. This happens to most new drivers. There are a lot of procedures when you are starting a car and some rookie drivers sometimes forget about the emergency brake. They accidentally leave it on, and the car feels slow.
If the emergency brake is weak, you probably won’t even notice this issue until later when your back brakes are almost done and burned out. To learn more, check out our overview of the emergency brake in a car.
So, always pay attention to the emergency brake and make sure that is always disengaged when you are accelerating the car. You even have a light on the dash that is turned on to remind you if you forgot to disengage the emergency brake.
There are other side effects if you forget about the emergency brake. Many parts of the car will suffer like the rear brake pads, as well as the clutch starting to smoke. This simple mistake could cost you a fortune to repair.
Why Is My Car Not Accelerating, Common Causes #3. Bad Or Low Fuel
Another in the line of simple reason why is my car not accelerating problem happens is the bad fuel that you are pouring into your tank.
Bad fuel can ruin your performance, even though most gas stations offer good fuel. There are still some of them that offer fuel with terrible octane values that aren’t good for anything.
If you are suffering from low performance in your car then the best idea is to go to a different gas station. Some cars run better on some fuels. Namely because of the additives that these gas stations add to their fuel. It makes the engines work much better.
Also, do not drive on reserve fuel. Don’t drive with your tank near empty because cars don’t like that. If you leave the tank near empty, the fuel pump may start sucking air. At this point, you will be left with poor engine performance.
This can also damage your injectors and make your engine run lean. So, remember – always get good quality fuel, and always fill your tank to more than a half. That’s if you want to avoid some of these problems from happening to you.
Why Is My Car Not Accelerating, Common Causes #4. Seized Brake Calipers
Another blunder is seized brake calipers. This is a problem where the calipers when they brake, seize in place and are applying pressure on the rotor. This pressure may eat through your pads very quickly.
When your caliper is stuck you will notice how one wheel has a lot more brake dust than the other. This is a dead giveaway of a broken caliper.
Another symptom is the poor acceleration of your car. If your car accelerates badly then it might be caused by something around the brakes.
This problem may also cause your car to be undrivable and create all sorts of issues on the road. So, if your car is not accelerating always check your brake rotors and calipers.
When you have a broken caliper, you will be able to repair it. A caliper can be repaired by replacing the pistons that apply pressure to the pads. These pistons age over time, as they can start to give up and stay in position. This results in the brake pads constantly being pressed by the caliper.
Fortunately, many companies offer rebuild kits for these calipers and you can easily replace them if you have some mechanical knowledge.
But it is worth noting that these new pistons do not last for a long time and sooner or later, you are going to experience this problem again.
So, we recommend that you replace the old caliper with a new one. It can be more expensive. But it’s worth it. A new caliper can cost $100 to $200. This, plus the labor is probably going to cost you around $300 to $400. But in the long run, it’s going to be worth it.
Why Is My Car Not Accelerating: Complex Problems
We discussed the simple things that can cause why is my car not accelerating problem to appear. And now let’s see the other problems that can cause your car to not accelerate very well. These problems are more complex and require deeper troubleshooting and car knowledge. But we are going to simplify these issues for you to have a better understanding of them and how they are fixed. So, let’s begin.
Why Is My Car Not Accelerating, Causes #1 – Ignition Issues
Ignition issues can make your car accelerate very poorly. These problems are not that complex and replacing these parts with brand-new ones will probably going to solve the issue.
Reasons #1. Bad Spark Plugs
Spark plugs are one of the integral parts of any vehicle. That being the art of creating explosions in the cylinders. They ignite the fuel and make the engine work.
Unfortunately, spark plugs sometimes tend to fail and develop some issues. And if they are in bad shape, they are going to cause your car to drive poorly and it will be difficult to accelerate.
Some of these issues are caused by carbon buildup if the fuel-to-air mixture is very rich. The spark plugs can burn when they have reached the end of their lifetime. Blistering appears if the spark plug is running a lean air-to-fuel mixture.
All these things can contribute to causing your spark plug to fail and result in bad acceleration. Since there aren’t any explosions in some cylinders, your car will be slowed down. So, it’s best to replace the broken spark plug with a new one.
Reasons #2. Bad Coils
Bad ignition coils (which you can diagnose by learning how to test a coil) are another ignition component that tends to fail and cause your car to develop some issues with accelerating.
The coils transmit the spark to the spark plug. If they are not in good condition, they will not deliver a spark and your car will run poorly. This can result in poor acceleration.
To fix this problem, you have to get a new coil and replace the old one. A new coil can be expensive and could cost more than $100. To find out more, check out our guide on how long can I drive with a bad ignition coil.
Reasons #3. Bad Distributor And Wires
Another problem, if you are running a carbureted vehicle, can be a bad distributor and wires. These distributors are known to fail as they age and develop rust on the parts that need to transmit the spark through the wires.
If your distributor is old, then it probably needs replacing. These distributors are usually changed with the wires. Wires are another piece of equipment that can fail on older vehicles. When both of these parts break, it can develop issues like why is my car not accelerating.
If these components are not transmitting the spark to the spark plugs, or if they are transmitting partially, the cylinders don’t work properly. At this point, your car is going to have problems. So, to get this thing resolved you need to replace the distributor and wires.
Why Is My Car Not Accelerating, Causes #2 – Sensor Malfunction
Problems with sensors may also cause your car not to accelerate. There are two sensors that can ruin your car’s performance and that is the mass airflow sensor and the O2 sensor.
Reasons #4. Mass Airflow Sensor
Mass airflow sensors can break, and when they do, it could cause all sorts of issues. These sensors basically measure the air that is sucked inside of the engine.
They are located right after the airbox. Their goal is to adjust the fuel-to-air mixture with the right ratio so that your engine performs at its best.
If the sensor is clogged with dirt or has broken, it may give the computer false readings. This will then cause the engine to work strangely and be low on power.
If you want to see the condition of the mass airflow sensor, you need to connect your car to an OBD2 scanner tool and diagnose the problem. The computer is going to tell you which sensor needs fixing.
Mass airflow sensors tend to be more expensive, and they can cost more than $100 for a new sensor. Always try to get the OEM parts or high-quality third-party units and stay away from the cheap copies because they would not last.
Reasons #5. O2 Sensor
The O2 sensor is another important sensor that when it breaks, can cause some major performance issues with your car. This sensor is located right after your catalytic converter. This sensor is measuring the level of oxygen that is inside the exhaust pipe.
And when this sensor gets clogged up or if it breaks, this will develop some serious problems, and could cause your car to deliver bad performance. It can also result in the engine misfiring as well as all sorts of other issues.
So, it’s best to replace this sensor. Namely, because this sensor is telling your engine how to work. And if the sensor is not good, your engine will not work properly. Among them is causing why is my car not accelerating problem in the process.
And you don’t want this to happen to your car. To see the condition of the sensor, you need to get an OBD2 scanner tool and scan the car for codes. If there are error codes related to this sensor, then it’s time to replace it. O2 sensors are also quite expensive and can cost more than $150 for a brand-new sensor. Same as the mass airflow sensor, go for OEM parts.
Why Is My Car Not Accelerating, Causes #3 – Engine Problems
If you are having a weak acceleration problem, this may be also due to the health of your engine. When your engine health is poor, then you will get only a portion of its performance capabilities.
If the engine parts don’t seal well, you may experience loss of compression, and this may result in poor performance of the engine and lower horsepower ratings.
The result will be slow acceleration. And even if the engine loses all the compression, it will simply going to stop working and will seize. Or the block could crack and destroy itself.
Engines usually last for around 200,000 miles with proper maintenance. Some of them last even more than this. So, when getting a new engine, make sure that it is in good health and is going to serve you for many more miles.
Why Is My Car Not Accelerating, Causes #4 – Faulty Fuel System
Problems with the fuel system may also contribute to poor performance, leading you to think about why is my car not accelerating. Some of these problems with a bad fuel system are going to be covered in this chapter.
Reasons #6. Clogged Fuel Filter
A clogged fuel filter can be one of the reasons why you are having a bad acceleration problem. This filter is designed to block all of the contaminants that are in the fuel.
This is because the fuel that we put in our tanks has some debris in it. That’s why fuel filters are there to purify the fuel that eventually goes to the engine. When these filters reach the end of their lifetime, they tend to clog and prevent the fuel from reaching the engine.
If there is some interruption of the fuel delivery system. This is going to result in why is my car not accelerating issue to appear.
To solve this problem, you have to replace your fuel filter. This fuel filter is located under the vehicle, usually close to the fuel tank, and is attached to the frame rails that hold the structure of the car.
Fuel filters are fairly inexpensive and can be easily replaced. So, if you are having a bad acceleration problem and your fuel filter has not been changed, maybe it’s time to go over its condition and replace it with a new one.
Reasons #7. Broken Injectors
Broken fuel injectors may also cause your car not to accelerate. If they have reached the end of their lifespan, they will not deliver the right amount of fuel to each cylinder.
If there is no right amount of fuel on each cylinder, this is going to result in poor acceleration or a possible engine stall.
To see the health of your injectors, you can connect your car to an OBD2 scanner and scan the car for issues. If there are codes on specific injectors, then you will know which one of them is bad and needs replacing.
The good thing is that for gasoline vehicles, the injectors are not that expensive and can be purchased quite cheaply. But if you have a big diesel truck, it may come pricey. Since diesel injectors are far more advanced technology and require a lot more precision in fuel delivery.
Why Is My Car Not Accelerating, Causes #5 – Other Miscellaneous Issues
In addition to the reasons and causes that we’ve mentioned thus far, here are some additional possible reasons why…
Reasons #8. Failing Throttle Body
The throttle body controls the amount of air that enters the engine. When you press the gas pedal, the throttle body opens up, allowing more air in, resulting in acceleration. Over time, carbon deposits can build up on the throttle body, causing it to stick or not open/close properly.
This can result in poor acceleration, rough idling, or even stalling. Periodic cleaning of the throttle body can help maintain its performance. If cleaning doesn’t resolve the issue, it might be time to replace the throttle body.
Reasons #9. Weak Fuel Pump
The fuel pump’s job is to send fuel from the tank to the engine. When it begins to wear out, it may not deliver fuel at the correct pressure, causing a drop in performance and acceleration. Symptoms of a failing fuel pump include sputtering at high speeds, power loss during acceleration, and hard starts.
A faulty fuel pump can leave you stranded, so it’s essential to address this issue as soon as you notice any of these symptoms. Regularly checking your fuel system can ensure that the pump and other components work efficiently.
Reasons #10. Damaged or Clogged Catalytic Converter
The catalytic converter is crucial in reducing exhaust emissions. If it becomes clogged or damaged, it can seriously impact your car’s performance. You might notice a significant drop in acceleration, reduced fuel efficiency, or a sulfuric or rotten egg smell.
Driving with a faulty catalytic converter not only hampers acceleration but can also damage other parts of the vehicle. It’s essential to address this issue promptly to maintain your car’s health and remain compliant with emissions standards.
Reasons #11. Slipping Transmission
If you press the gas pedal and feel a delay before the car accelerates, or if the vehicle seems to change gears for no apparent reason, your transmission could be slipping. This can be due to low transmission fluid, worn-out gears, or other internal issues.
Regularly checking and changing your transmission fluid can help prevent this problem. If you notice signs of a slipping transmission, consult with a mechanic immediately. Ignoring this can lead to more significant, costlier issues in the future.
Reasons #12. Tire and Brake Issues
Under-inflated or damaged tires can cause a drag, making it hard for the car to accelerate. Ensure your tires are in good condition and maintain the recommended air pressure levels. Additionally, dragging brakes, due to worn-out brake pads or a seized brake caliper, can hinder acceleration.
Regularly inspecting and maintaining your car’s tires and brakes not only ensures optimal acceleration but also guarantees safety while driving.
Reasons #13. Air Intake Issues
Your engine requires a specific mix of air and fuel to run efficiently. If the air intake system has leaks or blockages, it can disrupt this balance. Clogged air filters, faulty sensors, or vacuum leaks can cause a decrease in acceleration.
Regularly checking and replacing air filters and ensuring the intake system is free from leaks can help in maintaining your car’s acceleration.
Reasons #14. Electronic Issues
Modern cars rely heavily on electronics for various functions. Issues with the car’s computer (ECU), malfunctioning sensors, or wiring problems can lead to acceleration problems. For instance, a faulty throttle position sensor can misinform the ECU about the pedal’s position, leading to poor acceleration.
Regular diagnostics can help catch electronic issues early on, ensuring that your car runs smoothly and responds promptly when you need it to accelerate.
In conclusion, maintaining regular check-ups and addressing issues promptly is vital for the longevity and performance of your car. If you ever feel that your car isn’t accelerating as it should, consult with a trusted mechanic to diagnose and fix the issue. The road to smooth acceleration often lies in regular maintenance and timely interventions.
Why Is My Car Not Accelerating: In Conclusion…
In this article, we have covered a lot when it comes to the why is my car not accelerating issue. We discussed the simple issues that can happen to you like deflated tires, forgotten emergency brakes, and frozen calipers. All these simple things may cause your car to accelerate very poorly.
Then we covered some more advanced topics like the ignition system. Plus, we talked about which ignition system components can cause your car to drive badly. Things like such as spark plugs, wires, and coils tend to fail and develop a lot of issues related to engine power delivery.
Then we checked the engine aspect and we saw what engine issues may relate to the problem of poor acceleration. Engine issues are frequently on higher mileage vehicles that have a lot of miles on them.
And lastly, we have covered the problems with the fuel system. The fuel system is essential if you want the power to be delivered in the right manner. This system includes the fuel filter which can get clogged with debris, as well as the injectors that can break after many miles of use.
All these things have a proper solution. Yours is only to troubleshoot and see what works and what doesn’t to get your problem fixed.
Why Is My Car Not Accelerating: Frequently Asked Questions (FAQs)
If you’re still curious about why is my car not accelerating, our FAQs here might help…
Which Pedal Is The Gas
A car should have, at the very most, 3 separate pedals. On the far right, there’s the gas pedal, which is also sometimes known as the accelerator pedal. When you press and depress the gas pedal, you’re essentially actuating the throttle bodies. Thus, letting it know how much air and fuel to intake into the combustion chamber. The further down you press the gas pedal, the more air and fuel burns in the engine. Thus, it correlates with your car experiencing a boost of power. To the left of the gas pedal, there should be the brake pedal, which controls your car’s brakes. If you have a manual transmission, there should also be a clutch pedal even further to the left.
What Sensors Can Cause A Car Not To Start
If your car refuses to start, among the many potential causes could be sensor-related issues. Mainly, there’s the MAF (mass airflow) sensor and the O2 (oxygen) sensor. Primarily, their role is to let your car’s ECU (its primary computing power) know how much air and fuel are in the engine. The MAF sensor lets the engine know how much air is rushing into the engine. With this input in mind, the engine knows how much fuel should flow into the engine for an optimal burn, correlating with the volume of air. Meanwhile, the O2 sensor lets the ECU further fine-tune the air-to-fuel ratio by measuring the amount of oxygen in the exhaust fumes.
Why Won’t My Car Turn On
If your car won’t start, you’ll have to pay close attention to what noises it’s making. If you hear nothing at all, then it’s more than likely that your car’s electrical system has failed. Specifically, you might be dealing with a dead battery, a faulty alternator, or a bad ignition switch, among other possible faults. But, listen if you can hear a clicking sound. If so, this means that your electrics are working fine, but the engine isn’t turning over. It might be that the starter motor isn’t functioning properly. Or, the starter is working fine, but a clogged fuel filter or faulty fuel pump means that your engine is devoid of fuel.
Why Does My RPM Go Up And Down While Driving
It’s not normal for your engine speed (RPM) to fluctuate up and down while you’re driving, and are keeping a steady footing on the gas pedal. If so, this might indicate that your car has some problems to fix. Most of the time, worn-out spark plugs, vacuum leaks, and a bad idle air control valve would actively interfere with the smooth running of your engine. Thus, causing it to run more roughly and harshly, as shown by the RPMs bouncing up and down. Otherwise, the accelerator pedal position sensor might be faulty, too. Aside from that, dirty fuel injectors and transmission-related concerns may cause this issue, as well.
How To Make Your Car Accelerate Faster
If you want to make your car accelerate even faster, there are plenty of tuning work and modifications that you can try out. In some cases, a simple ECU re-program and flash is capable of unlocking a bit more horsepower from your car that was originally never tapped into. Other than that, you may want to consider removing excess weight from your car. This could be something as simple as emptying out the trunk, to gutting trim pieces altogether. Beyond this, you could take a look at simple modifications such as a new and racier exhaust system, or perhaps a cold air intake, and perhaps fit some performance tires to enhance grip.
