Idle Control Valve Testing Procedure

[TexasBlake]

I'm redoing my vacuum system, and wanted to check to make sure my ICV is working properly. I searched and didn't see a procedure on this site or on Clark's Garage, so I made one.

I also added it to my site, which can be seen here. My site is kind of like Clark's Garage, except I don't have nearly the number of articles he has, but I do try and take more pictures than he does.

This is part of my complete vacuum replacement of my '86 951, which I hope to make a writeup for.

Anyway, here's the writeup (minus the long introduction):

Hook up the power probe to a 12v power source such as your car body. Attach a alligator clamp jumper to the ground on the Power Probe (yellow) and another jumper to the needle of the power probe (red). Give the inside of the ICV a good cleaning. I sprayed carburetor cleaner first for cleaning, then WD-40 for lubrication.

There are three terminals on the ICV. The center terminal is positive, so attach the positive lead to this terminal. The two outside terminals are ground. The ICV works by swapping ground rather than swapping positive electricity.


Attach the positive jumper to the middle terminal, and the ground jumper to the top terminal. Give 12 volts to the ICV either by pushing the button on a Power Probe, or whatever archaic method you wish to use.


This should close the ICV.


Swap the ground jumper to the bottom terminal. Once again, give the ICV 12 volts.


This should open the ICV.


The action should be quick and snappy

[John_AZ]

Damm! you are a busy man

Very nice.

I have been using this link in the past--
Idle Valve

Thanks again.
John_AZ

[TexasBlake]

Originally Posted by John_AZ

Damm! you are a busy man

Very nice.

I have been using this link in the past--
Idle Valve

Thanks again.
John_AZ

Ah, there's a wealth of knowledge in that thread. I didn't search for ISV, so that's probably why I didn't find that thread.

[Razorback1980]

Originally Posted by John_AZ

Damm! you are a busy man

Very nice.

I have been using this link in the past--
Idle Valve

Thanks again.
John_AZ

I've never read that thread. What a great resource. Thanks John. ...and keep up the good work TexasBlake

[JimNap]

Ok, I performed the above test on my ICV and everything seems OK. Until I realized that my valve is mounted 180deg. from how TexasBlake has his mounted in the clamp.

So now the question begs - whose is right? Which direction should the arrow be pointing?

I'm hoping someone can also cite a source. I'm assuming everyone will say there 944 is running with it one direction so it must be right, but since both of ours seem to have been pulled in different orientations, I'm suspecting that it either doesn't make a difference - or it led to one of our followup problems.

Can anyone quote or paste a page in the factory manual that has this tidbit of information?

Jim
1985.5 944 NA

[JimNap]

Originally Posted by JimNap

Ok, I performed the above test on my ICV and everything seems OK. Until I realized that my valve is mounted 180deg. from how TexasBlake has his mounted in the clamp.

So now the question begs - whose is right? Which direction should the arrow be pointing?

I'm hoping someone can also cite a source. I'm assuming everyone will say there 944 is running with it one direction so it must be right, but since both of ours seem to have been pulled in different orientations, I'm suspecting that it either doesn't make a difference - or it led to one of our followup problems.

Can anyone quote or paste a page in the factory manual that has this tidbit of information?

Jim
1985.5 944 NA

For posterity purposes, I did find out they arrow was to point to the conenction of the intake plenum/s-hose (toward the firewall).

Good luck!

Jim