Good afternoon all,

Newly noticed issue with the 928. My ICV although fairly new seems to have stopped functioning. This morning it was a little colder than it has been recently and when I went to start the car it took several tries to start, it was starting and immediately dieing. After a few tries I had to start it with the throttle cracked open and hold the throttle open for around 15 seconds for it to start idling. It then had an extremely low idle ~500 rpm until it had warmed up a little.

I didn't have time to play around with it then but I just got a chance to look at it and jumping the B&C pins on the test plug doesn't effect the idle at all. Are there any other ways to test if the ICV is working?

Thanks
Eddie

 

check the fuses. spray deoxit on the fuse pins.

The ISV is a wear item in your year of system,
the only other way to verify its function is to remove it,
then use a pick to see if the armature turns freely.

NOTE if its worn then the armature/shaft will stick,
the stick is caused by the brushes wearing holes into the armature,
thus they will grab the armature and prevent it from moving

 

ISV has less than 5k miles on it. I will check fuses, are there any fuses that are specific to the idle control?

 

any chance that you might have swapped the ISV plug for the air cleaner temp sensor plug?
The ISV plug gives 12V,
the temp sensor gives about 5V.

NOTE if they are swapped the temp sensor in the air cleaner housing will be fried.

NOTE if switching the test port does not change the idle, then you have an issue with,
the ISV,
the power supply to the ISV ,
or the computer has been damaged .
NOTE computer damage is not a very common issue, but it does happen,
this can be tested by installing your computers into a known good running car,
then using the test port to disable the idle circuit

 

On a '86, the ISV plug has 3 pins not 2.

 

Doh your right maybe i was thinking of the 84 Euro

 

The ISV was working a month or so ago when I set the idle speed and CO. It seems unlikely that such a new ISV is bad, but bad parts do happen...

Where does the ISV get power from?

 

Are you sure it's not the Temp II sensor?