Low idle speed

[RS2Nut]

Hi,

I notice my car is idling at about 600 rpm which makes it quite lumpy at idle.

I have also found that when I turn on the AC the engine hunts up and down, to the point of allmost stalling,

Are these things connectd ?

What dictates the idle speed and is it adjustable.

Appreciate your advice.

Regards

PAUL

[scillyisles]

Sounds like your Idle Stabilisation valve is dirty and needs to be cleaned.

[RS2Nut]

Thanks scillyisles,

But, where is the idle stabilisation valve located and how do I clean it. Do you know if it is an expensive part ?

Thanks

PAUL

[scillyisles]

The ISV is just behind the intake manifold where the accelerator cable attaches. Look at this pic here it is the valve that sits behind the mainfold just in front of the front crossbrace . It has black tubing attached to it and is cylindrical in shape. They often get dirty and cause the symptoms you are getting (mine did) They can be cleaned by rinsing in petrol. http://pictures2.autotrader.co.uk/imgse ... 1314211510
I don't know the part cost but I would have thought it was not too expensive.

[DH79]

Just had very similar symptoms rectified by replacing the MAF....

[RS2Nut]

hi,

Downloaded the faulkts on VAGCOM today and it showed a faulty Lambda Probe....

Will replacwe it and let you know if that cures it..

PAUL

[RS2Nut]

Update

Replaced lambda probe, problem solved.

Got a Bosch one from Euro Car Parts for £47 delivered, was not straight forward though because you need to splice the cables. Took about 15 minutes....

Very smooth now...

Still idling a bit low so will give the ISV a clean and let you know ...

Regards

PAUL