What Causes Vehicle Shaking and Lack of Power During Acceleration?
2 Answers
The reasons for car shaking and lack of power during acceleration are as follows: 1. Severe engine carbon deposits: The most common cause of car shaking is a dirty throttle body or excessive carbon buildup in the fuel injectors. When there is too much carbon buildup inside the engine, the gasoline sprayed by the cold-start injector can be largely absorbed by the carbon deposits, resulting in an overly lean air-fuel mixture during cold starts and making it difficult to start. In this situation, the car will only start easily once the carbon deposits have absorbed enough gasoline to reach saturation. 2. Ignition system issues: Check the condition of the spark plugs, high-voltage wires, and ignition coils. Poor performance in the ignition system or weak spark plug firing can also lead to such symptoms. 3. Unstable fuel pressure: If you have already cleaned the engine carbon deposits, throttle body, replaced the fuel filter, and spark plugs, but still notice shaking at idle, it is recommended to visit a 4S shop to check the fuel supply pressure and the intake pressure sensor. Abnormal fuel pump pressure or incorrect readings and poor performance of the intake pressure sensor can both cause the vehicle to shake. 4. Aging engine components: Car shaking can also be related to worn engine mounts. Engine mounts are essentially the shock absorbers for the engine, responsible for absorbing minor vibrations during operation. If the engine mounts are faulty, these vibrations can be transmitted to the steering wheel and the interior of the car, causing shaking at idle.
I've been driving for many years, and it's always frustrating when I encounter acceleration shudder and lack of power. Common causes include worn-out spark plugs or faulty ignition coils, which lead to poor ignition and unstable engine operation. Fuel system issues are also frequent culprits, such as insufficient fuel pump pressure or clogged fuel injectors due to carbon buildup, causing inadequate fuel supply and resulting in shaky, sluggish performance. Another possibility is a dirty air filter, restricting airflow and making the engine struggle for breath, naturally leading to poor acceleration. Faulty sensors like the mass airflow sensor, if contaminated or malfunctioning, can cause the ECU to miscalculate the air-fuel mixture, increasing vibrations. I once experienced this on the highway—shaking like a sieve—so I immediately slowed down, pulled over, and checked the spark plugs. Replacing them fixed the issue. Regular maintenance of spark plugs and cleaning the fuel system is crucial; otherwise, prolonged neglect could lead to engine failure, costing far more to repair later.
