Does Your Car Jerk When Accelerating? (9 Possible Causes)

The average motorist gives little attention to their vehicle’s performance when all is operating as intended. However, this laid-back mentality quickly disappears the first time one’s vehicle bucks, jumps, or stutters when taking off from a stop or cruising at high speeds. In fact, the sudden onset of such symptoms often raises a significant amount of concern.

Unfortunately, singling out the root cause of such issues can prove rather difficult under many circumstances. This stems from the fact that a noticeable “jerking” under acceleration can be caused by one of several individual causes. Therefore, a certain degree of ingenuity is required to find a viable and worthwhile solution to the problem at hand.

We have formulated the following guide to assist in demystifying such issues as a whole, providing a certain degree of insight into the potential causes of a jerking sensation while under acceleration. In analyzing the guide below, you should find yourself better equipped to handle such issues as they arise in the future.

Read on to learn more about the various reasons that your vehicle jerks when accelerating.

See Also5 Reasons Your Car Shakes When Accelerating

Reasons Your Car Jerks When You Accelerate

There are actually many potential reasons for a jerking or lurching sensation to arise when a vehicle is taking off, or accelerating at low speeds. Understanding each of these potential reasons can prove valuable when attempting to remedy the issue at hand.

The following are several of the most common reasons that your car jerks when you accelerate.

1. Compromised Fuel System

bad fuel injector symptoms

Without proper fuel delivery, an engine can experience a host of troubling issues. One of the most common issues encountered centers around fuel injector failure or a general lack of fuel-rail pressure.

Either of these issues can rob an engine of horsepower, thereby leading to erratic acceleration. Likewise, a dying fuel pump can pose similar issues.

2. Poor Spark Delivery

An engine must also sustain proper spark delivery to each of its cylinders, in order to operate at maximum efficiency.

Worn/fouled spark plugs, damaged plug wires, and grounded coils can all rob an engine of its ability to deliver properly timed spark, thereby causing hesitation under acceleration.

See Also5 Reasons There’s Oil In Your Spark Plug Wells

3. Exhaust Restrictions

Another probable cause of engine hesitation under load is an exhaust-related restriction. These restrictions most often occur within the catalytic converter, which is somewhat prone to eventual failure over the course of a vehicle’s effective service life.

As a vehicle’s catalytic convertor clogs or fails, its filtration media becomes dislodged, thereby restricting exhaust flow as a whole.

4. Sensor-related Failures

In many cases, faulty feedback from one or more of a vehicle’s critical sensors can cause an engine to hesitate under load. One of the most commonly affected of all sensors in this regard is the MAF (Mass Air Flow) Sensor.

However, issues related to the engine coolant temperature sensor, MAP sensor, and crankshaft / camshaft position sensor can also cause issues of this type.

5. EGR System Failure

Modern gasoline-powered internal combustion engines feature EGR (Exhaust Gas Recirculation) systems. These systems allow a certain portion of exhaust gasses to be recirculated into an engine’s intake tract.

However, when an engine’s EGR valve sticks in the open position, thereby dosing these gasses at a higher density than anticipated, engine performance can be negatively impacted.

6. Vacuum Leaks

The introduction of unmetered air into an engine’s intake tract is known as a vacuum leak. Since an engine is not dosing enough fuel to compensate for this unmetered air, erratic operation under a load often results.

The only way to eliminate this issue is to find and fix all vacuum leaks that exist. While some leaks of this type are caused by dry-rotted hoses, others can result from compromised gaskets at various sealing surfaces.

7. Intake Restrictions

dirty air filter

An engine is also limited in its ability to perform as intended when intake airflow is restricted. This restriction can occur in several different ways, with a dirty air filter or dragging throttle plate being among the most common culprits.

A lack of clean intake air often results in unpredictable and erratic engine performance, which tends to manifest as a hesitation under load. Make sure you’re replacing your air filter at the recommended interval or in the case of a washable air filter, clean it according to its directions.

Read AlsoCan a Clogged Air Filter Cause Shaking While Idling?

8. Accelerator Cable Fatigue

Though the bulk of newer vehicles now utilize a drive-by-wire throttle body arrangement, some vehicles on the road today still feature basic throttle cables. These cables, with time, can begin to wear and fray, causing undue binding.

This, in turn, can cause a vehicle’s throttle response to suffer. In most cases of this type, throttle cable replacement is ultimately required.

9. PCM/TCM Issues

A vehicle’s powertrain control module and transmission control module work together to provide smooth, effortless acceleration under any array of conditions and circumstances. A fault within either of these vital controllers can easily limit a vehicle’s ability to accelerate as it otherwise would.

However, care is required when diagnosing such issues, in order to prevent inadvertently replacing an otherwise functional component.

Is It Safe to Continue Driving?

While the presence of the issues noted above does not necessarily make a vehicle undriveable, they are worth taking immediate steps to fix in almost every case, the underlying cause of a noticeable jerk under acceleration will only worsen with time, if not remedied.

This bears consideration, as nobody wants to find themselves stranded alongside the road.

With time, it is entirely possible for many of the above mentioned conditions to ultimately cause problems during starting or to usher in intermittent stalling issues.

Therefore, a hesitation or jerking while accelerating might serve as an advance warning of potentially worse issues to come. For this reason, one should not hesitate or procrastinate when troubleshooting issues of this sort.

In any event, the root cause of a vehicle’s jerking or stuttering concern should be thoroughly diagnosed and repaired at the first available opportunity. Doing so can quite easily prevent bigger problems from arising in the near future, many of which can be quite costly to contend with.

Making an appointment with a reliable service facility as soon as possible is advised if you do not feel confident handling such problems on your own or simply do not have the time to do so.

Steve Cooper

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