Toyota 4Runner engine jerks and loses speed while driving, unresolved after dealership visit on Toyota 4Runner

Some Toyota 4Runner owners report experiencing jerking and speed loss, particularly after dealership visits that failed to resolve the issue. Common causes identified include low or contaminated transmission fluid, which can affect performance. Additionally, worn-out spark plugs may lead to misfires and jerking, while a dirty throttle body can contribute to acceleration issues. Misfires, often related to spark plugs or coil packs, are frequently noted as a source of jerking during acceleration. Furthermore, a malfunctioning throttle position sensor (TPS) can cause RPM fluctuations and slow speed drops when the accelerator is released. Owners may also encounter problems with a faulty fuel pump, leading to irregular acceleration and decreased fuel efficiency. Lastly, issues with wheel speed sensors can arise, necessitating checks for damage and proper seating to ensure the VSC/TRAC system functions correctly. If these problems persist, further diagnostics or professional assistance is recommended to accurately identify the underlying cause.