Bending beam throttle valve does not return.

The reasons why the bent beam throttle does not return are: throttle position sensor failure, idle motor failure and so on.

1. Throttle position sensor fault: Throttle position sensor is used to detect throttle opening and speed. If the sensor fails, the throttle may not return normally.

2. Idle motor failure: Idle motor is used to control throttle opening. If the motor is damaged or stuck, the throttle may not return normally.