K jectroninc solenoid buzzing

[patanga]

Hi folks. Can anyone tell me what the electric solenoid on the back side of the K ject fuel distributrion / metering body is?... It has a blue Bosch style spring clip electrical connector if that helps. This device buzzes as soon as the ignition is turned on and looks to be attached to the fuel return side of the system.

Is this the 'frequency valve' and if so what does it do. I am Presuming that it maintains system back pressure to control the return flow of fuel back to the tank but I can't find anything in the Bosch manual to confirm.

Are there any diagnostics for this solenoid to confirm its operation and does anyone know if the item is available as my local Volkswagen dealer could not identify it on the VW spare parts system.

Thanks for your help.
Cheers

[h100vw]

There should be a part number on it somewhere.

VW often use this kind of valve to increase idle speed for when the AC is on or you turn the steering and the PS loads up the engine.

Can you do a photo for us.

Update your location, we might have suggestion for somewhere to take it.

Is the car Catalysed? Only the cat K-Jets are likely to have a frequency valve.

Gavin