Home TroubleshootingEngine Car Losing Power When Accelerating – Possible Causes And Solutions

Car Losing Power When Accelerating – Possible Causes And Solutions

by Kelvin Yates

Any car owner knows that stepping on the gas and the engine responding sluggishly is one of the worst driving experiences. It is pretty irritating and disappointing that your once efficient car is no longer eager to get you where you want in time. A car losing power when accelerating often results from an underlying problem in the vehicle’s mechanical or electrical system. In some cases, this issue can easily be solved by tweaking the carburetor, changing spark plugs, and maybe replacing the distributor rotor and cap.

However, vehicles are continuously more sophisticated and complicated. Auto-makers have done all this in an attempt to make their cars more efficient and improve the driving experience. The downside to this sophistication is that now there are many potential causes for when your car loses power when accelerating. It is essential to state that most or all acceleration power loss issues are related to the engine. Therefore, a problem with the engine is likely to cause power loss when you step on the gas pedal. Of course, there are other parts like the fuel system and exhaust system that can cause this issue as well.

This guide will walk you through all kinds of potential causes for a car losing power or hesitating when you step on the gas, so you won’t have to scratch your head anymore, wondering what’s causing your car to lose power when accelerating. We cover the why’s and how’s of engine power loss that you may have or are already experiencing as well as probable fixes to this problem. Let’s delve in.

Car Losing Power When Accelerating: Possible Causes

Engine Issues Of Why Car Losing Power When Accelerating

Bad Spark Plugs

The spark plug is an integral part of the workability of the car engine. The spark plug ignites a fuel/air mixture when an electric spark is delivered to the combustion system through the spark wires. This ignition of the air/fuel mixture, in turn, fires up your vehicle’s engine and delivers turning power to the wheels.  Therefore, the engine will naturally lose power if any of the spark plugs is down or fails. This will result in symptoms such as hesitating or power loss when you attempt to accelerate the vehicle.

car losing power when accelerating

Fortunately, you need not be a professional mechanic to identify a failing spark plug. One of the tell-tale signs that you have a bad spark plug is rattling or knocking-like noise coming from the engine compartment. Another symptom of a bad spark plug is reduced performance or deteriorating fuel economy. The condition of the spark plug directly influences the fuel economy of your car. Immediately check or inspect your vehicle’s spark if you notice a loss of power or that you go low on fuel quicker than before. Additionally, it is recommended that you have the spark plugs replaced every 30000 miles.

Dirty Air Filter

Surprisingly, clogged or dirty air filters are one of the most common causes for vehicles losing power when accelerating. This is because oxygen is a vital part of the combustion process, and lack of enough oxygen will lead to incomplete combustion. This, in turn, causes the engine to hesitate when you step on the gas pedal. Air from the atmosphere has to pass through the air filter before entering the internal combustion chamber. The air filter screens out debris, bugs, or other impurities that shouldn’t find their way into the combustion chamber.

After being used for a while, air filters tend to get clogged with dirt and debris. Once clogged, the air filter will limit the air passing through it and consequently into the combustion chamber. Clogged or dirty air filters negatively impact the workability of your vehicle. This is because the engine is unable to generate enough power to meet your acceleration requirements. This will therefore lead to the car hesitating every time you accelerate. If a dirty air filter is the cause of your acceleration problems, consider replacing and your car will run as well as new. There are reusable air filters that you can easily clean.

Poor Engine Compression

The car engine works on a basic principle that involves explosions that occur in the engine cylinders. The explosions generate a force that pushes the pistons, generating the turning force channeled to the wheels. The engine’s cylinders have to be tightly sealed so as conserve the force generated through internal combustion. A leak in the cylinders causes the compression rate to drop. However, an efficient engine has zero leaks, and therefore the compression rate is high. A higher compression rate means all the power generated by the explosions is utilized in turning the pistons.

Poor engine compression is a term used to describe when the engine’s cylinders are unable to contain the explosions occurring in them. This leads to low or no power when the car is accelerating. When the explosion power is leaking out of the cylinders, only a small portion of it is utilized to turn the pistons. This translates to lesser power being transferred to the wheels when you step on the gas pedal. Low or poor engine compression is one of the more serious causes of engine power loss. You, therefore, have your engine diagnosed by a professional for poor compression.

Possible Electrical Problems To Why Car Losing Power When Accelerating

For several decades, car manufacturers have fitted a series of electronic sensors in their car models to monitor the internal combustion process. The entire combustion process begins with an electric device. This is why it is important to consider electrical sensors and devices involved in the combustion process as possible culprits of the engine power loss when accelerating. Here are some possible electrical problems:

Ignition Coil Problems

An ignition coil is one of the integral parts of the ignition system that allows you to crank your vehicle’s engine. The ignition coil is connected to the battery and generates the electric current that travels through the spark wires to the spark plug. This “spark” allows the spark plug to ignite the air/gasoline mixture in the combustion chamber. The battery provides 12 volts, and the ignition coil converts it to over 20,000 volts. This amount of voltage is required by the spark plugs to generate a spark.

The ignition coil has to deliver the electric current at the right voltage and at the correct moment. For combustion to occur, the ignition coil must deliver at least 20000 volts at the correct timing as the cylinder reaches the top of its cycle.  If the ignition coil does not meet the correct voltage requirements or fails to deliver electric current to one or more spark plugs, the engine loses power. Incomplete combustion is notable by the poorly burned fuel exiting through the exhaust pipe of your vehicle.

MAF Sensor Malfunction

The MAF (mass airflow) sensor monitors and measures the amount of air flowing into the car’s engine. This data is relayed to the ECM engine control module. The computer interprets this data along with other information from other sensors. The ECM uses the interpretation to calculate the engine load. The ECM also uses the data from the MAF sensor to determine the amount of gasoline to create the perfect air/fuel mixture and the ignition timing. Having the right fuel to air mixture is important for delivering the appropriate power levels to match the engine load.

A MAF sensor malfunction negatively impacts the performance of your vehicle. It usually causes poor ignition timing, which may cause the vehicle to stall. One of the most common signs of a malfunctioning MAF sensor is the engine burning a low or high fuel to air ratio. This malfunction can be seen when the engine stalls or hesitates when you step on the gas pedal. Failure to deliver sufficient power levels to the drive shaft is directly reflected by the huge amount of power loss when driving.

Oxygen Sensor Malfunction

The oxygen sensor is located in the exhaust pipe of your car. It measures the number of gases exiting the engine through the exhaust system. The oxygen sensor measures the ratio of gasoline to air and sends the data to the ECM. As stated earlier, the ECM ensures the right amount of air and fuel enter the engine cylinders. With the data from the oxygen sensor, the ECM compares the amount of oxygen leaving the engine with that entering the engine. If the two values match, then the engine is in perfect running condition.

If the oxygen sensor fails or malfunctions, it affects the workability of the ECM, which in turn affects the performance of your car. Suppose the ECM does not receive accurate data from the oxygen sensor. In that case, it cannot calculate the appropriate fuel to air ratio required for the engine load, resulting in a lean condition. A lean condition will cause the engine to lose power when accelerating. It is essential to have a properly functioning oxygen sensor because it also affects the fuel injection system.

Camshaft Position Sensor Failure

Most modern vehicles rely on the Engine Control Module (ECM) to give specific instructions to different components of the vehicle. The ECM relies on a series of sensors, such as the camshaft position sensor, for information. The camshaft position sensor sends camshaft data such as speed to the ECM. The ECM uses this data to optimize the ignition timing and fuel injection. All modern cars have this module and therefore also have the camshaft position sensor. If the camshaft position sensor malfunctions and is not relaying the camshaft data to the ECM, then the vehicle’s performance and efficiency can be greatly compromised.

Fuel System Problems Causing Car Losing Power When Accelerating

Your car’s fuel system is responsible for ensuring that fuel is flowing between the fuel tank and the engine. Problems like power loss are sure to follow when fuel fails to flow to the engine. Here are some of the most common fuel system malfunctions that result in the engine losing power when accelerating.

Faulty Fuel Pump

The importance of the fuel pump to any car’s workability needs no reiteration. As the name suggests, the pump is responsible for moving the fuel from the gas tank to the engine, where it is combusted. Not only that, this pump enhances the efficiency of the vehicle by delivering the fuel at just the right pressure. It is important to ensure the right fuel pressure to meet the demands of different engine loads. If the car is idling, the fuel pump will deliver fuel at lower pressure compared to when you are accelerating. This enables the engine to achieve maximum performance.

If something were to go wrong with the fuel pump, it would either fail to deliver fuel to the engine or deliver it without the appropriate pressure. Therefore, if you have a faulty fuel pump, the vehicle will either stall completely or hesitate when you step on the gas pedal. Any malfunction of the fuel pump of your car will be directly reflected in the car’s performance. Therefore, it is very important to have the fuel pump inspected and checked if you notice even slight jeopardy in the engine performance.

Clogged Fuel Filter

Clogged fuel filters are another common culprit for acceleration problems in many vehicle models. Typically, the fuel filter is located between the fuel pump and the fuel injectors of most cars. The primary function of the fuel filter is to screen the fuel for any impurities like debris that may be in it. This way, when the fuel reaches the internal combustion chambers, it won’t have any impurities in it. The fuel filter acts as the only barrier between fuel contaminants and the engine. The fuel filter protects the engine and saves you expensive damage costs.

Over time, the fuel filter becomes clogged with all the trapped fuel contaminants. The filter is made of previous material and is designed only to allow gasoline to the fuel injectors. However, when it becomes clogged, the excess contaminants impede the flow of fuel to the engine. Limited fuel flow will negatively impact the performance of your car. Your car may work just fine when idling. This is because idling does have high fuel demands. The symptoms may only kick in when you attempt to overtake or drive up a hill. This is usually because the engine cannot generate the acceleration and power needed to achieve the tasks.

Bad Fuel Injectors

We have already covered how fuel moves from the gasoline tank to the engine of your car. What happens when the fuel reaches the engine? The fuel injectors come in. Fuel injectors are an integral management component of any vehicle’s engine. They form part of the fuel system of your vehicle. The primary function of the fuel injectors is to spray fuel inside the cylinders. This whole mechanism is controlled by the ECM, which dictates how much fuel gets sprayed. Using data from the sensors in the vehicle, the ECM determines how much fuel is appropriate and gives instructions to the injectors.

The fuel injectors should spray the right amount of fuel at the right intervals and patterns dictated by the ECM. This ensures the engine gives the best performance for different driving conditions. Most vehicles on the road today have fuel injectors in their engines. If the fuel injector fails or malfunctions, you can expect all sorts of performance problems to kick in. It’s important to have the fuel injectors in optimal condition. This enhances your vehicle’s performance and helps avoid problems such as a car losing power when accelerating. In case you find it challenging to replace your fuel injectors, the following video will be of much help.

Exhaust System Problems Causing Car Losing Power When Accelerating

Clogged Exhaust Pipe

If you are like most car owners, the tailpipe at the rear of the car is what you know about the exhaust system. The exhaust pipe, however, consists of pipes, a muffler, and a catalytic converter. The muffler acts as a silencing device and reduces the amount of noise coming from the engine. The catalytic converter works to remove or convert pollutant gases into gases safely released into the atmosphere. The exhaust pipe can be clogged by debris or dirt from the road. If you inadvertently back into a wall or pile of dirt, excess debris can enter the exhaust system and cause clogging.

The engine works on a basic principle that what comes in must eventually come out. If the exhaust pipe is clogged, there is a limited flow of exhaust fumes. This chokes the engine and causes a loss of power. As stated earlier, the exhaust system comprises an oxygen sensor that helps the ECM to determine the perfect air/fuel mixture needed for optimal performance. When there are restrictions in the exhaust pipe, the engine will not mix the right air/fuel ratio hence jeopardizing the performance of your car. This will lead to power loss when overtaking or driving up a hill.

Possible Solutions To A Car Losing Power When Accelerating

Regular Checkups And Cleaning

Sometimes all it takes to keep your vehicle running in top-notch performance is simple, regular cleaning and checkup.  Scheduling a regular visit to your local auto shop or mechanic for maintenance and cleaning will prevent most problems long before they occur. Most performance issues are directly related to failing engine components. However, you can eliminate the chances of your car losing power when accelerating by scheduling a routine cleanup and maintenance for your car. Timely detection of failing or worn-out engine components will save you expensive repair costs and enhance the performance of your car.

Check On The Connections

Everything in your car works off each other. Dominoes are a great way of visualizing how the engine components work. The dominoes won’t fall over each other if one of the components is malfunctioning. This malfunction can be caused by total failure or damage to the engine component. However, even if the component is in good condition, but not well connected, it will still malfunction. Having said that, the first thing you should do after noticing a malfunction such as power loss when accelerating is check on the connections. Check the wires, hoses, cables, nuts, and bolts for corrosion or damage.

Scan Vehicle’s Computer

It is always a great idea to scan your car’s computer for any error codes when experiencing problems such as power loss when accelerating. This should be done whether or not the check engine light is on. Scanning will reveal any pending error codes that need to be cleared or indicate an underlying problem with the car’s components. A computer scan is the easiest and possibly the cheapest way of diagnosing your vehicle for malfunctioning components. This makes it relatively to restore your car’s optimal performance and rectify or replace any bad components.

car losing power when accelerating

Inspect And Replace Essential Components

Replacing your vehicle’s clogged-up filters is the easiest potential solution to a car losing power when accelerating problem. It is recommended that you change the fuel filter after 30,000 miles or two years and the air filter after 14,000 miles of usage. However, you can replace them much earlier if they become clogged with contaminants. The possible causes of power loss in this article require the replacement of the broken or malfunctioning component. For example, if you determine that your car is losing power when accelerating due to a faulty fuel pump, sensor, or ignition coil, all you have to do is replace the component.

Low Engine Compression Solutions

We listed low engine compression as the most severe issue on this list. Low compression, as we discussed, indicates that pressure is somehow escaping from the cylinders. For most permanent fixes, the engine has to be taken apart completely to access the pistons and the cylinders. This is often a very expensive job, and you might even start considering a new vehicle. Although pricey, these fixes are necessary before you can use your car again. If a leaky valve is causing the low compression in your car, oil stop leak products are a great temporary fix. Eventually, you will have to replace the seal.

Car Losing Power When Accelerating Facts:

  • If a car is losing power when accelerating, it could be caused by many factors.
  • A clogged fuel filter or engine air filter is the most common cause of power loss while accelerating.
  • A damaged sensor, such as the MAF or O2 sensor, can also cause a disturbance in the air-fuel mixture.
  • A clogged catalytic converter or particle filter can obstruct the exhaust and cause power loss.
  • Faulty fuel injectors, worn spark plugs, and poor cylinder compression can lead to power loss as well.
  • A faulty turbocharger or boost pipe leak can cause a significant drop in engine performance.
  • A fuel filter that is clogged or dirty can be checked visually or by checking fuel pressure.
  • A dirty air filter can restrict airflow into the engine, causing reduced engine power.
  • Checking trouble codes with an OBD scanner and consulting technical service bulletins can help diagnose power loss.
  • If you lack the knowledge to fix the problem, take the car to a qualified mechanic for proper diagnosis and repair.

Car Losing Power When Accelerating: Final Verdict

Power loss issues when accelerating is both hazardous and disappointing. It is quite dangerous to attempt overtaking on the highway when your car does not pick up speed. Apart from putting your life and that of other road users in danger, acceleration issues make your drives boring and sometimes impossible. But as annoying and dangerous as this issue may be, the upside is that it’s fixable. The possible fixes will vary depending on the causes listed in this guide. Regardless of what causes your car to lose power when accelerating, it is imperative that you have it fixed immediately.

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