Fitting air idle control valve

[Gee21]

Hi all,

Just a quick question. I think my car needs an air idle control valve. When hot the engine ticks over perfect but every 15-20 seconds the revs drop to nearly cut out then bounce back.

Had it in to mechanic for some other work done and he has checked the base timing, the coil, all leads and replaced the spark plugs and he thinks it's the AIC so I've ordered one to give it a bash. £22

My question is, is it a case of plug in the new one and away I go or do I need to put the car into service mode first then set the tickover again as per the wiki document?

Many thanks in advance.

[HJ2]

Hi Gee,

I replaced mine without setting the base timing again.
Fitting is a pain in the a** as you can't see what you are doing, but it is definitely doable!

Take care that the O-ring does not fall off whilst refitting the new (yes, personal experience )

[Gee21]

Hi Gee,

I replaced mine without setting the base timing again.
Fitting is a pain in the a** as you can't see what you are doing, but it is definitely doable!

Take care that the O-ring does not fall off whilst refitting the new (yes, personal experience )

Thanks, just out of curiosity was you car having the same symptoms as mine above?

[HJ2]

Nope.

Since i had the head out for a gasket replacement i could easily change it for a new one, so i did

[Enright]

It sounds to me more like the throttle position sensor starting to play up rather than the IAC valve.
I don't remember the IAC valve being able to stall the car even when fully closed, and the more air it lets through, the higher the idle speed goes. Having said that I could be wrong, so good luck and please add your fault finding experiences to this thread to leave a trail...

[Gee21]

It sounds to me more like the throttle position sensor starting to play up rather than the IAC valve.
I don't remember the IAC valve being able to stall the car even when fully closed, and the more air it lets through, the higher the idle speed goes. Having said that I could be wrong, so good luck and please add your fault finding experiences to this thread to leave a trail...

Replaced the AIC today. The old one was thick with carbon and jammed open. Once replaced the revs were sitting very high so reset the idle speed and checked the base timing which was a mile out. Once that was done, car is purring like a kitten with no idle issues.

Happy days!

[Enright]

Thanks for sharing your experience, and glad it's all sorted now!

[donsladek]

Due to engine stalling at stops, looking to replace my Idle Air Control (IAC) soon and I'm wondering if anyone has any tips on how to accomplish this. Is removing the throttle body to get to the IAC the easiest, or should I work on this in place? Looks like a lot of parts/hoses in the way...any pictures or guidance would be helpful.

Thanks in advance for any suggestions!

[Simon_P]

A long time since I've done one but they are only held in by two M5 pozi setscrews. You can't see them but I don't recall removing the throttle body to get to them. Also, if one has seized you'll need to take the whole inlet off.

[Chas54]

Don

Ive just taken my Idle Air Control valve off. I got to it by removing the bonnet, removing the coolant header tank and a few hoses. The right hand screw is not visible but I got one hand in to touch the screw head and guide a Posi drive screwdriver onto it with the other hand. I fished the O ring out the hole with a finger afterwards.
I am looking for what causes my occasional engine revs dropping off when pulling up ,at junctions etc. I know the valve is operating as I have Elanscan but it seems erratic sometimes.

Anyway , now its out, the valve face is very shiny on one side and pitted a bit on the other. I think its a linear stepper motor of some sort so I am guessing the shiny face always touches the same side of the valve seat in the engine. I have to work out a way of viewing the valve seat now. I will replace my valve I think, they are cheap enough .
Hope your removal goes allright.

regards
Charlie

lotus IAC (2).JPG

[JP Galway]

Hi,

I'm in the throes of replacing the IAC valve. I didn't have to do anything as drastic as removing the bonnet. However, I have removed a couple of the thin pipes (possibly vacuum pipes) and another pipe. I'va also previously removed the large air intake rubber tube and I've moved the water reservoir out of the way. To remove the screw that I now couldn't see, I used a mirror to see where I needed to go with the screw driver. The IACV on my car was attached with phillips screws, not torx screws. A bit dodgy trying to poen these. I will be replacing with Torx screws! With the hoses/pipes out of the way, I was able to see and more easily get at the 2nd screw. It had seized and I was able to get a small vicegrips in there to help with open the screw. I had, over two previous days, dosed the screws with WD40. I'll let you know how I get on.