Idle speed - 16v

[Egyvalver]

My 16 valve was idling very badly - it would not go below 2000rpm. I have had the ISV changed and the car's CO/timing etc set up properly which cured the major problems i was having but despite the idle screw being wound as far as it will go the car will still not idle below 1100 rpm when warm. The car starts and runs beautifully so it is not causing me any problems other than I know it should  be at 950 +/- 50 rpm and this bugs me!!

My question is this then: is this caused by the 'auxilary air valve' not closing properly once the car is warm? I have a vague memory of someone saying on this forum that if you pinch the soft pipe coming off the inlet elbow and the revs dip (which on my car they do) then this is indeed the case?

If this could well be the case then is there anyone out there who can provide me with a part number and give me some help as to what the part looks like?

Cheers for any help you can give
 

[jezza16v]

Try cleaning out the throttle body with carb cleaner, you'd be surprised how much black smeg gets in there. Sometimes its enough to stop one of the two main butterfly valves from closing properly. Take the idle screw right out and clean the small airways out as well. 

[clipperjay]

Could be the old blue temp sensor?
Does she smoke and what colour is it?

[Gambit]

aux air valve/diaphram is operated via the throttle closed switch on throttle body. to test the switch & valve simply hold the throttle open over 2k with your hand and press the throttle closed micro switch. if its working the rev's will plummet & then rise again. and continue doing so while u hold the switch closed

alternativly it sounds as if you have a lot of unmetered air getting in. check your injector seals

[Egyvalver]

cheers guys for help.

The car doesn't smoke at all - blue or white.

It has had a genuine brand new throttle switch fitted as well recently.

Jezza - i will also try cleaning out the throittle body etc, although the chap that works on my car says he has done this

Gambit - I will renew the injector seals as this is a fairly cheap and easy way of eliminating one potential cause. Cheers

however this still brings me back to the point i made in my initial post, although maybe my terminology is wrong. As i said, when you pinch the breather (?) coming off the inlet elbow the revs dip to around 850 rpm and as i said i have a vague recollection of someone saying that this is the test to see if some valve is not shutting properly. Could it be the warm up valve that i am thinking of?

Sorry for my confusion!

[mattkh]

It is the ISV you are referring to

[Egyvalver]

I have found where i had read about this and it definitely sounds like the auxilliary air valve

http://www.auto-solve.com/mech_inj.htm#MFI12

handy site!

cheers for your help