Car Jerks When Accelerating (All Causes and Repair Methods)

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If your car jerks when accelerating, there might be a fuel or ignition system problem. However, most of these problems are fixable, and you don’t always need the help of a mechanic.

Car Jerks When Accelerating ~ Ran When Parked This article will discuss the causes and repair methods for your jerking car.

Why Does a Car Jerk When You Accelerate? (8 Reasons)

A car jerks when you accelerate because of faults in the fuel system, spark plugs, exhaust system, EGR system, or vacuum system. MAF sensor failure is also a cause of shaky acceleration. Moreover, worn accelerator cables or failing powertrain and transmission command modules commonly cause these problems.

Jerky Car Due To Fuel System Failure

One of the reasons for a car jerking is fuel system failure. These failures stop a consistent supply of fuel from entering the engine. With the inconsistent fuel pressure, you can hear stuttering noises from the engine.

When the fuel flow is irregular, the car accelerates irregularly. Problems with the fuel system that result in a jerky car include dirty fuel injectors and bad fuel pumps. In both issues, the check engine light illuminates the dashboard.

Why Car Jerks When You Accelerate ~ Ran When Parked

If you do not drive your car for some time, the fuel evaporates when exposed to heat. Evaporation leaves deposits that can lead to clogged or dirty fuel injectors and pumps. Moreover, old fuel in the tank accumulates dirt over time, which may block the injectors when you start driving.

The car may also shake if you have clogged fuel filters or jammed fuel lines. The filters ideally stop any impurities in the fuel from entering the engine, but a clogged filter will restrict the fuel flow and result in a jerky experience. Similar restrictions in the fuel line can block the passage of fuel.

Other fuel system failures that cause a jerky drive include leaks in the damaged fuel system or using low-quality fuel. If your car’s fuel system leaks, the fuel in the tank will not reach the engine. It can also impose a fire hazard if you wait to fix it.

Insufficient Car Engine Spark

Faulty spark plugs can answer the question, “Why is my car stuttering when I accelerate?” Spark plugs are essential to the combustion process, providing the spark required to ignite the fuel. Sometimes, the plugs stop working correctly for one reason or another.

The car jerking meaning can be explained by inconsistent ignition of the fuel. The check engine light also indicates this problem.

Spark plugs produce bad sparks because of the following:

  • Engine misfire
  • Overused sparking plug
  • Overheating in spark plugs
  • Faulty ignition coils or plug wires
  • Using the wrong type of spark plug
  • Poor car care and missing routine tune-ups
  • Carbon accumulation or corrosion on electrodes

Old vehicles have a distributor cap responsible for providing current to the spark plugs. So, if you own an older model, your car might be jerking because of a faulty distributor cap.

Blocked Car Exhaust Components

In some cases, the exhaust components of the car, such as the exhaust manifold or muffler, get damaged. A blockage from the damage keeps the exhaust gases in the exhaust system.

For instance, a clogged catalytic converter can cause massive pressure to stay in the engine. The gas pressure generated by a blocked catalytic converter causes the cars to rough idle.

The exhaust failure due to the blockage is what causes a car to jerk when stopped. Moreover, the blockage may cause moisture buildup in the engine.

The following exhaust problems also cause a shaky car:

  • A loose or damaged exhaust manifold
  • Exhaust leakage causes the engine to run lean
  • A clogged oxygen sensor causes the engine to run rich

Failing EGR Shakes the Car

The Exhaust Gas Recirculation (EGR) system controls the emission of nitrogen oxide gases. It redirects these gases back into the car, but if you notice that your car jerks when accelerating no check engine light, you might have a stuck or failing EGR.

Your car’s EGR system might be failing due to carbon buildup. The EGR valve lies in the exhaust system, exposing it to hot and polluted gases. These gases contain carbon particles that sediment on the valve with time and restrict the gas flow.

Although some cars have an EGR cooler to cool down these gases, the system is at risk if the cooler gets damaged due to high heat. The pollutants, dirt, and debris can clog the EGR passages and create a shaky driving experience.

Other problems affecting the EGR system are:

  • Using low-quality fuel
  • Decreased vacuum pressure due to leaks
  • Damaged valve due to exposure to foreign objects, heat, and electrical problems

A faulty EGR valve causes the exhaust gas to enter the intake manifold. It clogs the manifold and makes the car vibrate. Moreover, the exhaust gas has harmful pollutants that roughen the engine.

The EGR valve might get stuck in an open or closed position. Both problems have different symptoms but affect the engine’s performance.

The failing EGR system also causes damage to other engine parts, which in turn shakes the car. In this case, the car jerks while driving at constant speed as well.

Air Control Sensor Malfunction Issues

The mass air flow sensor collects information on the air entering the engine and provides it to the Engine Control Unit (ECU). Maintaining air quantity is essential, but a faulty mass airflow sensor leads to an irregular air-fuel ratio inside the engine.

Car Air Control Sensor Malfunction Issues ~ Ran When Parked

As a result, the car faces ignition problems, and sudden power loss occurs while driving. The car jerks when driving on highway because of inconsistent power. You can detect this issue if black smoke rises from the tailpipe.

Old vehicles use a carburetor to mix the air and oil in the correct ratio. So, a damaged carburetor can be the case if you own an old car.

Faults occur in the air sensors due to the following reasons:

  • Overheating due to sun exposure or heated engine
  • Contaminants in the sensor, such as dirt and debris
  • Damaged wiring or connection with ECU
  • Physical impact

These problems make the vehicle jerk and cause rough idling, decreased engine power, and increased fuel consumption.

Air Intake Restrictions or Vacuum Leak

The vacuum system in the engine is responsible for providing pressure to the various parts of the engine. The vacuum pressure is created when the pistons move down, pushing the air into the cylinders.

Vacuum leaks can occur when there is some damage to the tubes. Consequently, unwanted air gets in the engine and ruins the air-fuel ratio. The car hesitates while accelerating because of the excessive air intake by the engine, and you will feel that it jerks at high speeds.

Your car may also shake due to intake restrictions, for example, a clogged air filter, restricted throttle body, and a collapsed intake hose. These problems prevent air from entering the engine and disturb the combustion mixture.

Jerky Car Due To Damaged Acceleration Cables

The acceleration cord or cable links the engine’s throttle plate and the pedal. It is an integral part of the acceleration systems. If the cables are faulty, they provide inaccurate signals to the throttle plate.

It leads to irregular amounts of fuel used in the car for acceleration. Due to this, the car jerks when releasing accelerator. The acceleration cable can get damaged due to the following reasons:

  • The metal cable has a rubber cover that becomes brittle over time and gets damaged
  • Improperly adjusted cable undergoes stress and friction and breaks
  • The cable corrodes due to moisture or chemical exposure
  • The cord may get damaged in a car accident

You shouldn’t neglect this issue because a worn accelerator cord causes a loss of control over the vehicle. If left unattended, you might damage the engine or risk your safety.

Issues With Command Modules of Powertrain or Transmission

The Powertrain Control Module (PCM) controls the engine and vehicle emissions. It is also the part responsible for checking the entire car for any faults and indicates damage by showing a light on the dashboard.

On the other hand, the Transmission Control Module (TCM) is the component of the car that focuses on automatic transmissions. PCM and TCM work together to give the car a good ride with minimum shaking.

Some problems in these modules can lead to jerking. The reasons for their failures include:

  • Electrical issues such as short circuits and power surges
  • Physical damage due to road impact or accident
  • Exposure to extreme hot or cold temperatures
  • Damage from water exposure

How Do You Fix a Car That Jerks When You Drive at High Speed?

To fix a car that jerks when you drive at high speed, you need to occasionally get your vehicle a tune-up. It will help diagnose damaged parts such as air filters and brakes and replace them. Cleaning the injectors or replacing damaged cables can also fix a jerky car.

Get a Routine Tune To Restore a Smooth Drive

A routine tune-up is essential for car maintenance. You can also take your vehicle to the repair shop, and the mechanic will check various car parts.

Fixing a Car That Jerks When You Drive at High Speed ~ Ran When Parked

They might find old or worn-out spark plugs and replace them with brand-new ones. The auto repair mechanic will also replace dirty air filters or fuel filters and faulty ignition coils.

Moreover, a steering wheel, tire, or brake inspection may help them find a defective component causing car problems. The tune-up also includes checking fluid levels such as engine oil, coolant, or transmission fluid.

Get Cleaners for Fuel Injectors and Catalytic Converter

It is always a good choice for a car driver to invest in cleaners for fuel injectors and catalytic converters. You can get them at automobile or online shops because injectors must be cleaned often.

Cleaning the injectors is a straightforward process:

  1. Open the fuel cap and pour the cleaner into the fuel tank.
  2. Fill the entire tank with the oil. This will mix the oil with the cleaner.
  3. Now, hit the road for a test drive.

Your catalytic converter may also need some good cleaning, but using cleaners directly on the converter is not a good idea. If your converter is clogged or damaged, it is best to take it to a mechanic.

Replace Damaged Cables and Sensors

Figure out if there is any damaged cable or sensor. You can do this by using some diagnostic techniques, consulting a qualified mechanic, or using a car manual. If you find damaged components, replace them or take your car to a good mechanic.

Here’s how you can replace worn accelerator cables:

  1. Park the car and make sure you pull the parking brake.
  2. Find the cable running between the gas pedal and the throttle body. You can consult the user manual.
  3. Disconnect the bolts holding the cable to the throttle body and pedal.
  4. Install the new cable and adjust its tension.
  5. Car Jerks When Accelerating Conclusion ~ Ran When Parked
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