All:

While checking things out on how to replace injectors, I noticed that the Air Flow Sensor Plate pulsates / vibrates up and down while idling.

It is not an insignificant vibration - rather it is noisy and vibrates visibly. When it is doing so, if I disconnect the connector from the frequency valve and reconnect it back again, the vibration stops. Then again if I rev it up and let go, it starts vibrating again when it comes back to the idle position. If I rev and then very gently let it back to idle position, it does not vibrate.

Any ideas on what could be the reason. Am I looking at a new frequency valve ? Can I clean / refurbish the old one.

Thanks,

Amit