Why Does My Car Slow Down Then Speed Up?

Why Does My Car Slow Down Then Speed Up

You may have been driving your car for years, but you can notice that it is moving differently. It will slow down and speed back up again.

Why is this so? Is something wrong with your car?

Why does it slow down and speed up again? Well, there are two reasons for this problem.

The first is you have low transmission fluid. The second is because of a faulty transmission control module (TCM).

These are the issues that you might have been facing. These issues are hard to diagnose.

To resolve this problem, you must go to an auto mechanic. The mechanic can bring back the prior condition of your car.

If you want to know more about this topic, you can watch the following video:

Top Reasons Why Your Car Is Not Accelerating Properly

1. Slipping Clutch

You cannot accelerate quickly if your clutch is slipping. It does not matter if your engine is working perfectly.

When the clutches are old, they usually slip. Also, when they are contaminated with oil or grease.

2. Clogged Exhaust

Combustion gasses may not be able to get out from your tailpipe very easily. This will cause a buildup of back pressure.

Thus, the ability of your vehicle to make power will be hindered. When your exhaust is clogged, you must resolve the problem as soon as possible.

Exhaust gasses can cause a fire because they are very hot.

3. Bad Spark Plug Wires

If the spark plug wires have bad insulation, the electricity that should go across the spark plug will be prevented. Thus, the accelerator will not work properly.

4. Bad Spark Plugs

Spark plugs are needed to power your vehicle. When they are worn out, your vehicle will have reduced performance.

5. Neutral Gear

There can be times when you do not pick up the speed of your car because you have changed into Neutral gear. Whether you accidentally change it or not, your car will rev its engine and will not accelerate.

This can happen when the stick shift is easy to move.

6. Bad Throttle Position Sensor

You can analyze the opening angle of the throttle valve through the throttle position sensor. Once the information is detected, this information is sent to the engine control unit.

When this process malfunctions, the gas pedal cannot control the speed of the car.

7. Electronic Error

When the electronic system that controls your car has errors, it cannot determine the fumes that will be generated by your car rightfully. The central computer or electronic control unit (ECU) will limit your capacity to accelerate.

8. Dirty Fuel Filter

Fuel cannot pass through the fuel filter when it is clogged with dirt and debris. When the fuel cannot enter the engine, you cannot make your car accelerate when you step on the gas pedal.

The solution for this is you need to replace your fuel filter.

9. Bad Timing Belt

You have to know that your timing belt should be in perfect condition. If one tooth of the belt is worn out, you will have acceleration problems.

Not replacing the timing belt at the right time can make the entire teeth of the belt break off. The belt can snap altogether when this happens.

This will leave you stranded. You can also have expensive damages.

10. Air Flow Meter Problem

There is an air flow meter that computes the mass of air in your vehicle. The information is sent to the engine control unit.

The mixture of air and fuel is calculated through this. But if the air flow meter has a problem, it can give wrong information.

As a result, you will have slow acceleration.

11. Oxygen Sensor Problem

Oxygen sensors monitor the exhaust emissions of your car. They determine the amount of fuel that is needed.

If the oxygen sensor malfunctions, there will be the wrong amount of fuel. This can result in a rich fuel mixture that can cause slow acceleration.

12. Air Delivery Problems

The air filter can have dirt, debris, and other impurities that can prevent good combustion of your car. A clogged air filter can affect acceleration.

13. Fuel Delivery Problems

The common culprits are clogged fuel tank strainers, defective fuel pumps, and failing fuel injectors. A clogged fuel system can be a cause of low engine power.

Thus, you can have slow acceleration.

14. Ignition Problems

Ignition systems are needed to ignite the air and fuel mixture. When they are not working properly, you will have slow acceleration.

15. Emission Control Sensors

Emission control sensors must be working properly. If the ECM (electronic control module) senses a problem, the engine power will be reduced.

You will have slow acceleration.

16. Mechanical Issues

If your car does not accelerate properly when you step on the gas pedal, you should get professional help immediately to repair your car. Not considering mechanical issues can lead to expensive repairs.

Your car will not accelerate properly if you have mechanical issues.

If you want to learn more about why your car is not accelerating properly, you can watch the following video:

Top Reasons Why Your Car is Losing Power

1. Ambient Conditions

Your car can have a higher intake air temperature when it is hot. It can make the engine more prone to knock.

When this happens, the computer has to take away the ignition timing which lessens power. The air conditioning can even make the situation worse.

It will be hard for the engine to work. There will be less air in it.

This means that less fuel will also be injected into your car which can make your car not make as much power.

2. Low Cylinder Compression

High cylinder compression is vital in giving your car enough power. When you have low cylinder compression, your car will struggle on an incline.

The engine power will not be strong enough.

3. Faulty Camshaft Position Sensor

The camshaft position sensor computes the camshaft speed and gives the information to the ECM. Through this, the ECM can manage the ignition and fuel injection timing rightfully.

But if the camshaft position sensor is faulty, there will not be good timing. The power of the engine will be limited.

4. Bad Ignition Coils

When ignition coils wear, you will lose insulation. There will be no sufficient voltage that can reach spark plugs.

Your car will not have much power. This can also result in a misfire.

5. Clogged Fuel Filter

When you step on the gas pedal and you get a minimal output, this denotes that there is a problem with your fuel system. More likely, you have a clogged fuel filter.

A clogged fuel filter can make the fuel pump work harder to bring fuel into the system. This will result in a slow insufficient drive.

Your car will not have the power that you need.

6. Bad Spark Plugs

When spark plugs age, their ground electrodes wear out. There will be no spark or combustion that can lead to a misfire.

No power will be generated for the car.

7. Bad Fuel Pump

If you have a bad fuel pump, it may not work at all. Your car will starve for fuel.

Your car can run idle and with a low load. You cannot expect it to have much power.

8. Clogged Fuel Injectors

As fuel injectors age, they can become clogged. When this happens, it affects the injector’s capacity to atomize the fuel.

The fuel will not reach the combustion chamber. No power can be made for your car.

9. Vacuum Leak

Vacuum leaks can affect the overall performance of your vehicle. You can test this using a smoke test.

Be sure that the air system is sealed properly.

10. Clogged Air Filter

Clean air is needed to be mixed with fuel to make the engine have the power that it needs. But if you have a clogged air filter, what can you expect?

Air filters can be clogged by impurities like debris and bugs. When this happens, the engine can be damaged.

So, you have to clean your air filter. Be sure that air can continue to pass through it.

You have to ascertain that it can enter the chamber without any impurities. If not, the engine will not have enough power.


Why Does My Car Suddenly Slow Down While Driving?

When your car suddenly slows down while driving, you have an issue with the fuel filter. Your fuel filter must be clogged.

The fuel filter filters the dirt and debris from the fuel system. Over time, it has to be cleaned.

When the fuel filter is clogged, the fuel pump will work harder. Your driving will become less efficient.

Why Does My Car Increase Speed Up on Its Own?

Sudden acceleration can happen when there is an electronic malfunction in your car. The throttle can expand and can make the vehicle accelerate without you pressing on the gas pedal.

A defect in the electronic system can cause the mechanism of the car to malfunction.

Can Low Transmission Fluid Cause No Acceleration?

Having low transmission fluid cannot generate much hydraulic pressure. This will lead to gear slippage.

Gear slippage will lead your car to not accelerate properly. Your car will move sluggishly because of low transmission fluid.

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