What causes jerking when a car suddenly accelerates?

[DiSophie]

The reasons for jerking when a car suddenly accelerates are as follows: 1. Fuel quality issues: Using gasoline with a lower octane rating. Insufficient octane number in gasoline can lead to weak acceleration, resulting in decreased engine power and increased fuel consumption. 2. Engine oil quality: Insufficient oil pressure or poor sealing. Poor-quality engine oil can also cause insufficient engine power, reduced fluidity, and increased driving resistance. 3. Blockages: Components such as the air filter or throttle valve are clogged or malfunctioning. This leads to insufficient air intake, causing weak acceleration, slow speed increase, and a jerking sensation. 4. Ignition system problems: If the spark plugs are severely carbonized and ignition is poor, it can also affect engine acceleration.

[DeDante]

The other day when I was driving my old buddy on the highway, it suddenly jerked during acceleration, which scared me into slowing down immediately. Later, the repair shop found out that the ignition coils were aging, and two out of the four cylinders had unstable ignition, causing intermittent power during hard acceleration. If spark plugs haven't been replaced for too long, this can also happen easily, as metal fatigue leads to excessive gap. Also, if the transmission fluid deteriorates, an automatic transmission will shift roughly, especially in older cars that require extra attention. I’ve developed a habit of replacing spark plugs every 50,000 kilometers, and avoiding flooring the gas pedal too often in city driving—being gentle with the throttle can extend part lifespan. By the way, a clogged air filter can also cause insufficient air intake, making the car feel like it’s gasping for breath during acceleration.

[DeLuke]

Handled many similar cases. Sudden jerking during rapid acceleration is 90% caused by power transmission interruption. For manual transmissions, it could be worn clutch discs causing uneven engagement. Automatic transmissions more often suffer from valve body blockage or solenoid valve failure. Fuel system issues are also common - like carbon-clogged injectors causing intermittent fuel supply, especially noticeable when tank is low. Insufficient fuel pump pressure shows similar symptoms, particularly sensitive during hill climbs. Recommend using borescope to inspect cylinder carbon buildup during each maintenance. Always choose major fuel brands - small gas stations have more impurities that can clog fuel lines. Don't wait for problems to occur, regular inspections are key.

[LaDerek]

My hot hatch had this issue after modifications. The mechanic said it's mainly due to ECU tuning mismatch. Turbocharged cars are more prone to this - turbo lag combined with confused gearshift logic during hard acceleration makes it feel like being jerked. Incorrect air-fuel mixture ratio can also cause jerking, which might be caused by dirty oxygen sensors or faulty intake pressure sensors. Those who modified exhaust systems should pay attention to backpressure balance - too low backpressure affects low-end torque. Now I've learned my lesson: professional matching is mandatory after performance modifications, and avoid frequent hard throttle inputs during daily driving since modified parts are more sensitive than OEM components.