Multiple operating elements within your car work together to move your vehicle forward. The throttle of the engine is the primary step in car acceleration. Your car’s throttle pedal is directly connected to the engine and regulates the airflow in the throttle body for fuel injection.
A spark causes the engine’s piston to go down and rotate the crankshaft. As the throttle pedal approaches the floor, more air is taken in, causing the crankshaft to rotate more quickly. This is what allows your car to accelerate when driving.
However, If you’re driving your car and losing power as you speed, there are only two possibilities. Either you don’t have enough petrol, or you don’t have enough power in your vehicle.
There are several causes for your car to lose power significantly while accelerating. The most typical causes of a car not accelerating while driving include a faulty sensor, contaminated fuel or air filters, or a faulty timing belt. Generally, this isn’t something you should ignore.
Reasons Your Car Won’t Accelerate When You Push the Gas
Here’s some bad news: There isn’t a one-size-fits-all answer as to why your car might not be accelerating as it should.
To figure out the root cause of the problem, you (or your mechanic) will need to do some troubleshooting. It’s important to consult a repair manual or repair database to determine the correct diagnostic procedure for your application.
Usually, you’ll find one or more of the following issues to be the root cause of poor acceleration:
#1. Dirty Oxygen Sensor.
Every car is equipped with an oxygen sensor, which works in tandem with a mass airflow sensor. The airflow filter can become clogged with dirt and contaminants, which in turn impacts vehicle performance.
The dirty sensor may impact your car’s ability to accelerate, and you might also notice a decline in fuel economy too. You may need to have a mechanic check the oxygen sensor, the mass airflow sensor, or both.
The oxygen sensor will likely need to be replaced if it is dirty, while the mass airflow sensor can simply be cleaned. A dirty sensor may prompt the “Check Engine” light to come on in the car.
How to Fix: Using an automotive scan tool, determine which sensor is malfunctioning. Replace the O2 sensor.
#2. Malfunctioning Throttle Position Sensor.
The Throttle Position Sensor in your car, sometimes called the “TPS” for short, can also cause acceleration issues. This sensor directs the computer in the engine to adjust based on the engine’s throttle valve opening.
The sensor can get dirty or break, which means that it won’t accurately determine the throttle position. The sensor will provide inaccurate information to the engine, which can lead to reduced vehicle performance and will cause the car to accelerate more slowly.
How to Fix: Replace the throttle position sensor.
#3. Clogged Fuel Filter.
Every car has a filter in the engine called the fuel filter. The fuel filter’s job is to clean and purify the fuel that enters the vehicle. The engine fuel filter also allows adequate amounts of fuel to reach the engine.
If the fuel filter becomes clogged with contaminants, it won’t provide the engine with the clean fuel that it needs to run correctly.
Additionally, the pollutants that enter the car’s system end up in the fuel tank, where they can break up and ultimately impact the car’s performance. Swapping out the fuel filter for a new one should resolve the issue.
How to Fix: Replace the fuel filter.
#4. Dirty Air Filter.
The engine also has another filter called the air filter. The air filter supplies the engine with the air that it needs to work properly.
The air filter can become dirty, which in turn reduces clean airflow to the engine.
How to Fix: Replace the air filter. If you have a reusable air filter like K&N, follow the directions on cleaning it.
#5. Mass Air Flow Sensor Clogged or Malfunctioned.
The mass air flow sensor (or meter) is located and attached to the inlet air cleaner. Since the function of the air flow sensor is to measure air mass that is flowing into air intake, a clogged or bad mass air flow sensor could send the wrong data to the engine ECU for calculating the air fuel mixture.
A very common symptom of an air flow meter malfunction is car that struggles to pick up speed.
How to Fix: Clean or replace the MAF sensor.
#6. Bad Fuel Injector.
Fuel injectors are responsible for delivering fuel to the engine, and if they’re not functioning properly, your car will likely not be able to accelerate properly.
A dirty, clogged, damaged, or faulty fuel injector may restrict the flow of fuel to the engine, which can result in poor acceleration, hesitation, or even stalling.
How to Fix: Use a diagnostic scan tool to read error codes from the car’s computer. If the error code indicates a problem with the fuel injector, you can try cleaning it with a fuel injector cleaner. If cleaning doesn’t work, replace the fuel injector.
#7. Limp Mode.
Limp mode is a safety feature that is designed to protect your engine from damage. If your car’s computer detects a problem with the engine, it may put the car into limp mode, which limits the engine’s power and speed.
This undoubtedly will cause your car to have acceleration issues, and may also be accompanied by a flashing check engine light.
How to Fix: Using an OBD2 scanner, scan the car’s computer for fault codes to determine what exactly is causing the vehicle to go into limp mode.
#8. Faulty Fuel Pump.
The fuel pump is responsible for delivering fuel from the gas tank to the engine. If it’s not functioning properly, it can cause a lack of fuel pressure, which can lead to poor acceleration. Symptoms of a bad fuel pump include sputtering or stalling while driving, difficulty starting the engine, and a decrease in fuel efficiency.
How to Fix: Replace the fuel pump.
#9. Timing Belt.
This component is as it sounds. The timing belt is something like a VIP in the list key of components of an engine. If this belt is off even by 1 tooth, it may cause some pretty notable acceleration problems.
How to Fix: Replace the timing belt.
#10. Slipping Clutch.
If you have a manual transmission, a slipping clutch can cause acceleration problems. This happens when the clutch disc fails to engage properly with the flywheel, causing what feels like your car has lost power while driving. It’s similar to a person trying to run on ice.
Signs of a slipping clutch include a burning smell, difficulty shifting gears, and poor acceleration.
How to Fix: Replace the clutch.
#11. ECU.
The ECU, or engine control unit, is responsible for regulating the performance of your car’s engine. If it’s malfunctioning in some way, it could be causing your car to have trouble accelerating. A faulty ECU can cause a variety of other issues, including misfires and poor fuel economy.
How to Fix: Repair or replace the ECU.
#12. Clogged Exhaust.
Two major components of your car’s exhaust system are your catalytic converter and muffler. If either one of these becomes clogged or damaged, this can restrict exhaust flow and lead to a reduction in engine power and acceleration.
This is especially the case with turbocharged vehicles which require proper exhaust flow to work as intended.
How to Fix: Check all components of the exhaust system to look for clogged or damaged parts. Replace if necessary.
Checking for Trouble Codes
If your car won’t accelerate, one of the first things you should look for is the Check Engine light. This light will come on if there is a problem with your car’s engine or emissions system. It’s worth mentioning that the Check Engine light does not always mean that there’s a major problem. Sometimes, it can be a minor issue that can be easily fixed.
To check for trouble codes, you will need an OBD2 scanner. This is a device that plugs into your car’s OBD2 port and reads the codes stored in your car’s computer. Once you’ve connected the scanner, you can retrieve the trouble codes and get a better idea of what is causing your car to not accelerate properly.
Once you see what trouble codes have been stored, you can use them for diagnosis. These codes will give you a better idea of what is causing your car to not accelerate properly.
But the fact is that trouble codes don’t always pinpoint the exact problem. In some cases, the codes may be related to a minor issue that can be easily fixed. In other cases, the codes may indicate a major problem that requires immediate attention.
If you’re unsure what the codes mean, have a mechanic diagnose further – don’t rely on the codes alone.
Acceleration Problems’ Impact on Fuel Economy
When your car won’t accelerate properly, it can have a significant impact on your fuel economy. Poor fuel economy is a common symptom of a car that won’t accelerate as it should.
You may think that if your car is accelerating poorly, it’s using less gas so your fuel economy should be better. But the opposite can actually happen!
If your car is struggling to accelerate, it means that your engine is working harder than it should, which can lead to increased fuel consumption.