ICV (idle control valve) or ISV (idle stabilizer valve) O-Ring
 

Found an o-ring that fits quite well. A bit thicker than the original, but that should prove better. A bit of petrolem jelly, and in it went. Will easily withstand the temps on top of the head. The Military Standard number is MS28775-219.
You can get 2 of them from amazon for 99 cents
Military O-Ring MS28775-219 (1-5/16 ID X 1-9/16 OD X 1/8 W) Nitrile 75A (Pack of 2): Amazon.com: Industrial & Scientific

SHIPPING ( at Amazon) $7.50!!
:0
But good to know the dimensions you found.
J_AZ

Hey Volhv,

My ICV just stopped working and I took it out of the car and have it apart right now. I've searched and haven't found any info here that helps me. I think my resistance readings are wrong but I can't find what they are suppose to be. Do you happen to know? Everything seems to check out find from what I know. What was wrong with yours, other than the oring?

Here is what I found. Volhv may have already installed the ICV.

1. Clean the ICV with carb cleaner and a lot of "Q" tips. Both sides.
The inside rotating valve should move with little force -OPEN and CLOSE

This is a picture of a dirty ICV

http://forums.pelicanparts.com/uploa...1377789094.jpg

http://forums.pelicanparts.com/uploa...1377789122.jpg

http://forums.pelicanparts.com/uploa...1377789141.jpg

The resistance readings.

Center pin to out side LEFT or RIGHT pin ===about ~ 22 OHMS +-
Outside LEFT pin to Outside RIGHT pin=====about ~43 OHMS

The CENTER pin is the 12 volt POS connection.
The outside pins are 12 volt NEG connections.

If you connect the center pin to the 12V POS battery wire and just touch each outside pin with the NEG battery wire--just for a second!---the valve valve will turn inside the ICV

See TexasBlake info:

Idle Control Valve Testing - Porsche 951 - www.texasblake.com

GL
J_AZ

Thanks John, That's what I was looking for. I have mine all apart and it very clean now, you can eat off of it. My resistance reading are 22 and 43 just like they should be. I will test it with a 12v source today, but now I'm worried that I might have a wiring problem. Since the ICV is fine, and the resistors on the DME are fine(swapped DMEs), I think the only thing else it could be is a wiring problem or maybe a ground?

Can someone explain what the o-ring is for? None of the cleaning or testing procudures mention an o-ring anywhere.

Maybe???

http://forums.pelicanparts.com/porsche-944-turbo-turbo-s/330312-idle-valve.html

Unless Volhv had something else in mind?

J_AZ

Grounds are supplied by the DME. Check the connectors, wires, insullation, wiggle the DME cable GENTLY.

FIRST----Here is info on the ICV.
http://forums.pelicanparts.com/5310676-post10.html

Here is the pin printout on the DME 35 Pin connector. SEE pins 33 & 34...

http://forums.pelicanparts.com/uploa...1377818928.jpg

Last test?

http://www.the944.com/idle86.htm

GL
J_AZ

John, Thanks for the pin info, that helps a lot. I can see what the reading are on those wires to see what the problem is. I'm thinking my problem is either a ground somewhere, where ever the DME gets it's ground from. Or one of the wires are broken. I have 2 944s so I have swapped parts back and forth and My ICV is fine and the DME is fine, so I know it's somewhere in the middle.(the wires) I think I know where the wire might be broken too. I think I might have done it when installing a power door lock kit. Thanks for all the help and sorry for taking your post Volhv

Well, I found my problem. One of the wires #33 was broken, which was cause by me. I fixed that wire and now my ICV works. It's vibrating like it should. Now I need to order some gaskets and put everything back together. Thanks guys.

Good job Mr. Giraffe

Ha ha, Thanks Andrew

Yep, that's the o-ring. It goes where the aluminum meets the steel..... after you pry the tabs apart.

I'm very glad this thread turned into such a great pool information.

Just checked my spare valve, and I have the same resistance readings. When I replaced my vacuum hoses, all I did was clean and check the operation of the one i have in there now. Hopefully soon, I'll swap it out for the one I've just resealed.

I passed my emissions test, but the NOX was very close to the limit..... so hopefully this is the culprit.

So... how and when does the ICV operate. It looks to me, like it's either open or closed....