Detecting a fault ISV

[corozin 0]

Is there a simple (non-diagnostic) test to detect if your Idle Stabilisation Valve is faulty or sticking? For example is it safe to unplug the connector when the engine's warm to see if the hunting stops? Or is it possible to see anything wrong by hooking up a multimeter.

 

Car is a VR6. Any suggestions appreciated!

 

Cheers

John

[millerman 0]

if the problem is bad ideling normally its your MAF unplug that if its still bad theres your problem

[corozin 0]

Thanks - that's the first check in the morning then

[millerman 0]

also have a check on vacum hoses they can bugger it all up too :D

[Yandards 0]

You can put the ECU into final control element diagnosis mode using VAG-COM, this allows you test that all the injectors and the ISV is working within limits.

 

It will be under the engine option on VAG-COM, select Final control diagnosis box and it should run through the fuel injectors 1-6 and then onto the ISV, you should be able to feel the ISV buzzing if it's working correctly.

[Supercharged 2]

Non-paper air filters kill ISV's...

 

There was brand new one on eBay - £99 bargain!

[corozin 0]

Thanks for the tips all.

Have already found a better price than eBay for a potential replacement (http://www.worldcarparts.co.uk/tabid/14 ... fault.aspx) - just £76!

 

Also interesting to note the wide range of VW & Audi models this particular Bosch ISV found it's way onto.

[veedub16v 0]

have you tried cleaning it?

[GVK 0]

Clean it, measure the resistance across the terminals (should be able to find what it should be)

 

:shrug:

 

Convert to 0BD II :clap:

[8vMatt 1]

also have a check on vacum hoses they can bugger it all up too :D

 

Just wondering if these are the ones going from the back of inlet manifold to the Carbon canister?

 

If so, one of mine has melted on the exhaust shield about three quarters through :gag: Guess this won't be too good for idling?

[corozin 0]

Clean it, measure the resistance across the terminals (should be able to find what it should be)

:shrug:

Convert to 0BD II :clap:

 

Already converted mate :)

[Supercharged 2]

OBD2 doesn't use an ISV? :?

[Yandards 0]

OBD2 doesn't use an ISV? :?

 

True, it uses a stepper motor on the throttle body to open and close the butterfly instead.

 

OBD 2 should also give around 2-5 MPG extra, smoother idle and a much better pull through the gears - which is nice.

[Jay23Sx 0]

What car are we talking about? On the early C's the ISV power comes from a little white connector right by the coil. The Haynes manual (red Golf one) says to unplug this if you want to test the ISV. (it also says to disconnect it when you're setting the screw on the throttle body)