Throttle valve wear in 2.1 WBX

[Mr Bean]

To be honest I have an old Techtronic knocking about somewhere which I dug out of a skip and sellotaped back together and used for many years experimenting with sound to light machines and the like. It was very basic and that was it's best feature for me. It had a green three inch circular screen and just Spot position, Volts per division and scan rate. I do find my more complex scope a bit of a faff to remember how to operate.

Google oscilloscope app. There is some interesting stuff on there - that little one for about £20 could be OK for not too demanding stuff.

Thanks for you response to the AFM question. Your logic looks good to me. I think it might have cleared a mental block on my part

[937carrera]

I think it might have cleared a mental block on my part

Best not go telling Mrs Bean that

[itchyfeet]

In my tests on my van ( and some spares I had )

Idle valve should NOT pass air through ( tried blowing through it) with no power
With just ignition on and connected you can blow through it and it should vibrate quite a bit.
Refit it and start the engine and the vibration is not so easy to feel, when running if you pull the plug off it stalls either hot or cold ( which means it's function is not just at cold idle)
If you pull the controller out when running it stalls also ( I assume no power to valve it closes)

The valve is held open by the ECU with the controller doing something ( perhaps PWM who knows)

If yours does not vibrate it implies either it or the controller is not working.

The valve provides a variable bypass for the throttle and by unplugging it you have made it close so no air passes and by opening the screw the air needed is passing by the throttle, bear in mind you have set your throttle body up with ( probably) a faulty idle valve so perhaps you already opened up the throttle screw far more than you would have done with a working idle valve hence why it didn't stall.

I suggest if you want to measure the signal to the valve with a 'scope you extend the wires, I think they are 2.8mm spades in the connector from memory so you don't have to cut the loom just buy some spades and make a male female extension, then you can get the wires you are measuring well away from the vehicle and best to use a current probe.

Pics for interest for those who don't know what we are talking about

[937carrera]

I may as well post the Samba link I looked at last night which describes how it works and why it can cause fast idle

https://www.thesamba.com/vw/forum/viewt ... p?t=542448

[937carrera]

and further googling turns up the digifant manuals with the relevant idle electronics

http://www.westfaliat3.info/Vanagon_Pro ... _86-91.pdf numbered page 30

http://www.vanagonauts.com/files/Vanago ... System.pdf numbered page 121

[itchyfeet]

I I have unearthed the Idle Valve Controller lurking behind the RHS rear light cluster and found the multi way connector spades completely covered in green verdigris and locked solid into the mating harness connector.
.

my solution

[itchyfeet]

[937carrera]

my solution

it's the same solution to the pneumatic central locking module in the boot of the 6N2 Polo - do it to the Lupo if you haven't already

[itchyfeet]

my solution

it's the same solution to the pneumatic central locking module in the boot of the 6N2 Polo - do it to the Lupo if you haven't already

lupo has no central locking but I have a Polo 9n3 with central locking?

#offtopic

[itchyfeet]

Here's a couple of useful downloads for you DJ owners

http://www.vanagonauts.com/files/Digijet_FI.pdf

not working?

[937carrera]

I checked the URL and it's the same as the one I used the other day.

However, the whole domain seems to be down, hopefully it will be back soon and it isn't down to all the club8090 owners getting the download