bureau13

My idle has always been a little high...around 800rpm or a little bit more, I'd guess. I never bothered with it. But lately, it's become significantly worse...just not consistently so. Starting from cold, it's now around 900-1000. However, after driving it a bit, it's now up to 1200-1400. If it's up near 1400 and I goose the gas, it usually settles back to the 1200 vicinity, but it will end up back up near the upper range if I drive a bit.

I do not appear to have a throttle linkage issue, from what I can tell. Idling, I can't go under the hood and get it to drop by jiggling anything. Car off, I can tell that the idle switch is being activated (I can hear it).

I saw some descriptions of ISV testing, so I jumpered ports B and C on the diagnostic plug, and...the idle jumped up when jumpered. I thought I read that it should go down. So I'm not sure what that means...

If it were a vacuum leak, wouldn't it be more consistent?

Any hints or areas to look at are appreciated. '85.6 S3 manual, btw...

928NOOBIE

Several of us S3'ers have had similar experiences...idles OK when cold and as you drive it idle goes up higher and higher the hotter it gets. For me it was a new ICV that fixed it.

bureau13

Dumb question...when you say ICV, is that the same thing I mean when I said ISV? The thing under the intake with the three-wire connector? When you were having the problem, did you jumper the pins on the diagnostic port to see if it was supposedly working?

bureau13

OK, apparently ISV and ICV are synonymous. I found a lot of additional info searching this forum using "ICV."

I also found some references to the S3 part being the same thing used on a number of BMWs of the era. There are some Ebay sellers with one for around $40, which was noted in one of the threads, but I don't know if anyone has tried one? I'm not sure what the options are these days....the one at O'Reilly seems to be NLA. I've got an email in to Roger, so whenever he gets back I'm sure he will let me know my options...

bureau13

The only other one I've found is here: http://www.rockauto.com/en/moreinfo.php?pk=817751&jsn=3

It's also on Amazon with a 1-2 month wait, for just under two bills. But it's "Standard Motor Products," not Bosch. I have no idea if that is a problem...but I haven't found the Bosch part anywhere.

Randy V

Have you tried 928 International or 928sRus?

bureau13

I have an email into Roger, but I think I read he's on vacation. From other threads, it seemed like people were having issues finding them.

928NOOBIE

Yes we were having trouble locating them a year or so ago. Believe it or not I found them on Pep Boys website...they were branded as Borg Warner but when you got the unit out of the box it was the bosch unit...there were 3 or so left and they got snatched up presumably by the others in our community having similar issues at the time.