What Causes the Unstable Throttle and Jerking in Diesel Vehicles?
2 Answers
The reasons for unstable throttle and jerking in diesel vehicles are as follows: 1. Fuel pump issue: Problems with fuel supply. If the fuel pump pressure is insufficient, it may lead to premature aging of the pump. In such cases, it is recommended to replace the fuel pump promptly. 2. Clogged or leaking fuel filter: It is advisable to replace the fuel filter for testing. The fuel filter's role is to filter impurities in the fuel, improving fuel quality and enabling the engine to achieve better fuel efficiency. It is recommended to replace the fuel filter every 1-2 years. 3. Clogged fuel injector leading to poor fuel atomization: This may cause misfiring in a single cylinder or multiple cylinders, resulting in severe engine shaking during idling or acceleration. It is recommended to remove the fuel injector and use professional testing equipment for diagnosis. 4. Damaged spark plugs or ignition coils: This can also lead to poor ignition in the vehicle, causing the engine's power output to jerk and become very unstable. Since spark plugs are prone to carbon buildup or aging over time, regular replacement is recommended.
I've been repairing diesel vehicles for ten years, and the most common issue of unstable throttle with jerking movements is usually due to fuel system problems. Clogged fuel injectors causing uneven fuel supply lead to shaking, or an aging fuel pump with unstable pressure results in jerking. A dirty air filter restricting airflow can also cause the engine to struggle. Faulty sensors like the throttle position or crankshaft position sensors sending chaotic signals make the car spasm. Carbon buildup in the EGR system blocking the intake is especially common during city traffic jams. A slow turbocharger response can also add to the lag. I recommend starting with simple checks: replace the air and fuel filters to see if there's improvement. If not, use professional diagnostic tools to read ECU fault codes. After all, diesel systems are sensitive to impurities, and regular maintenance can prevent issues before they escalate, avoiding costly repairs later. Safety-wise, unstable throttle can lead to loss of control at high speeds, which is dangerous. If you notice the problem, slow down immediately and seek a reliable repair shop for diagnosis.
