cleaning the ICV / cure for erratic idling

[king nero]

The part circled in yellow is the cause of erratic idling.
It's the ICV, or idle (air) control valve.

Either it's dirty and stuck, and needs cleaning, or the wires that connect to it are broke due to engine vibrations [ EM (engine management) light should come on in this case]

Parts to undo:

• the control plug (unclip the wire springie thingie at the back, but take a look in advance, so you'll remember how to put it back on
• The two rubber hoses, attached by clips, easily undone by either a flat screwdriver, or a 6 mm socket 

You'll probably find that the rubber hoses are stuck on (due to old age), either cut 'em off and replace the hose, or take a toothpick or a very fine screwdriver, and pry underneath the hose, thus loosening the grip it has on the collets.


Now you should have the ICV in your hand, free from all connections.
You'll notice a rotational valve inside, with probably black stains on it.
It should be able to rotate clockwise if you look at it from the open end (opposite the electrical connector), until the hole is completely open. (rotation of about 45 degrees).

I used petrol (didn't have anything else), but you can use carb cleaner as well. (precautions! gloves, goggles, no smoking, ...)
Try to rub all the black stains off, using a toothbrush or a pencil.


Oil it slightly where the parts move (I hope mine won't freeze shut!)
(see post below, no engine oil as it's too thick, I used gun oil which is about as fine as it gets, but CLP or clean / lubricate / protection should do the job just fine)


Re-assemble, check and double-check all connections and don't forget your screwdriver under the bonnet.


Part number of the long hose that connects to the ICV:
08-26888 / GM 90 354 693

and you'll also need a piece of the same diameter, of about 1.5 - 2 inches in length for the short hose

(The collets are 22 mm or .866" , so you could always use a suitable garden hose in emergency situations... )



ps, Colonel K, I didn't use the huge arrow pic for obvious reasons  

hosted on my site: http://kingnero.be/engine/icv.html

[blippi]

nice write up m8

[HMK]

Yes, I use petrol, but be careful - Highly Flammable & wear protective gloves (petrol is not good for the skin). I have also used 'Blue Meths' & some people use paraffin. I use proper '3 in 1' light oil to finish off with, NOT engine oil (it's too thick).

Remember that the short piece of wiring that goes from the ICV to the loom can eventually break due to engine vibration, causing intermittent operation of the valve & showing a 'fault code 57' & lighting the EM light intermittently.

[king nero]

edited my original post - some useful info added

if anything else should be mentioned, just say so!

[bstardchild]

Yeah best way is

Drop it in an ultrasonic bath filled with carb cleaner for 3 mins

Not everyone has one of these so

Alternative is to 3/4 fill the thing up with carb cleaner and shake it vigorously for a min or two with your fingers blocking the holes up empty and repeat till the carb cleaner fluid comes out clean.

WHY

Well it's the bits you can't see that need cleaning the comutator and brush assembly are all at the opposite end to the rotary valve and when these get gummed up with oily deposits the action gets jerky and slow

Lightly oil with WD40 or duck oil - 1/3 fill shake and empty the excess
 mins

[DOMINIC]

Tanks K NERO for your reply i hope to do it on sunday weather permiting.
Any chance of reposting photo as it did not show up at this end.

[vauxhalljohn]

did mine a couiple of months ago , soughted out my poor idling problem and the engine managment light has not been on since . plus ecceleration improved .

simple job takes a good half hour , unless your like me and do a thorough job and clean everything  so its shiny again . lol .

[therealeasterbunny]

^^^^^ wot they said ^^^^^

... and here's my bit for good measure ...



Above: Here's the sucker with two hoses / jubliee clips and connecting wire held on with springy clip at rear



Above: Here it is removed - note the springy clip ... make sure you keep a tight grip on this sucker when taking off or it could s~p~r~i~n~g off anywhere in your engine compartment, never to be seen again ...



Above: This pic is to give you an idea of the electrical clip - once spring is off, pull this clip off pulling away from the unit toward the bulkhead - should just slide off ...



Above: Off and got some carb cleaner spray ready ... Niknaks optional



Above: We can see inside is pretty gunked up with oily goo.



Above: Don't put your finger in, it gets dirty!



Above: Inner valve also gunked up



Above: Fill the sucker up with carb cleaner fluid



Above: This is whatr came out after leaving it for a few minutes without any shaking or wiping - just poured the liquid out. Then resprayed and shook for a couple of mins until clean fluid coming out.



Above: Shiny and new innards - at this point, add some 3 in 1 oil lube as described in above posts.



Refitting is reversal of removal - watch out for that clip again!



THEN YOU'RE READY TO CRUISE...

Not covered above is cleaning the rubber hoses and also the gauze in the rocker cover ... COMING SOON!

[flash911]

ahhhhhh now i know where mine is on the estate I can do mine, but will wait for the next instalment of hose and gauze 

[Pedro]

Excellent post, Mr. Bunny. 

[carlton_mad]

i have to ask why do you remove the clip you just squeeze the "ears" together and off she jolly well comes!!!

[therealeasterbunny]

i have to ask why do you remove the clip you just squeeze the "ears" together and off she jolly well comes!!!

D'oh!!! Thanks very much for the tip ... !  I didn't know that! No longer will I search for the spingy thing on top of my gearbox

[carltonman]

Did you oil the ICV afterwards?

[vauxhalljohn]

ive never oiled the icv after ive cleaned it , did not realise you had to
now i know , did the icv when i got the dippy back afew weeks ago.

[Pedro]

You need to lubricate the moving parts and 3-4 drops of light oil (3-in-1) is all you need.

Don't use engine oil - it's too thick.

[vauxhalljohn]

thanks pedro , i think i will do that before i head out to yorkshire next week .

[melinx]

I don't believe that it's a good idea to use 3 in 1 oil on the ICV !

If you use any oil containing silicone, it's likely to damage (or even kill) the lambda sensor.

You should never use anything containing silicones anywhere around the engine if there is the slightest chance that it could reach the lambda sensor; apparently a trace amount is enough to 'poison' it

WD40 specifically says on the tin that it does not and never has contained silicone: Perhaps significantly 3 in 1 (made by the same company) does not have that assurance !

[melinx]

It is worth noting that only WD40 and Duck Oil are mentioned by bstardchild for lubricating the ICV and Duck Oil is also stated to be Silicone free

Some days ago, I emailed the manufacturers of 3-in-One asking their assurance that it did not contain silicones and explained why the unintentional use of silicones can damage or destroy a lambda sensor.

There has been no reply so draw your own conclusions

[Pedro]

I can't see that three of four drops of 3-in-1 in the ICV will make their way to the O2 sensor with a plan to kill it!

[melinx]

Don't know, I can only go on statements made by the sensor experts and they say that even using gasket sealant with silicone in it will screw up the sensor: I would imagine that only gives a trace amount of silicone

[melinx]

I have finally had a reply from the manufacturers of 3-in-one and feel it's only fair to them to reproduce their answer (with their permission of course)

Many thanks for your enquiry via our website:

"WD40 specifically states that it does not contain Silicones. Another of your products 3-in-one multi purpose oil spray does not carry that assurance. The motorist forum of which I am a member recommends its use on the Idle Air Control Valve. My concern is, that any trace of silicones could impair or even render inoperative the exhaust gas Lambda sensor. Could you please clarify/give assurances that it does or does not contain silicones ?"

 

Our 3-IN-ONE Oil does not contain silicone.

 

If I can be of further assistance please do not hesitate to contact me direct.

 

Kind regards

Lisa

 
Lisa Hart
UK Sales Administrator
 
Tel: 01908 555462
Mob: +441908266938
Email: Lisa.Hart@wd40.co.uk
 
 
WD40 Company
Brick Close
Kiln Farm
Milton Keynes
MK11 3LF
www.wd40.co.uk

[Whippit]

So thats OK then

[Jimmy]

so rinse it out with Carb cleaner untill clear, then lube with WD40 and reasemble?

is that right?

[Whippit]

I read it that 3 in 1 is OK, which is good as I have always used it

[melinx]

I have found that WD40 has far less permanence than 3-in-one so by all means, use 3-in-one