you can test it by unplug it to see if there's any change. The 1st week I
got my van it idles OK but not great... then I discover ICU (behind the
passenger tail light) was disconnected. I re-connect it and it idle worse,
erratic...

On Thu, Oct 16, 2014 at 9:44 AM, Stuart MacMillan <stuartmacm@gmail.com>
wrote:

> Just got my son's "new" '87, and we were told by the seller it had an idle
> problem.  He's driven it about 200 miles with nothing more than a bit of an
> idle surge once in a while, but now it won't idle at all cold, and when it
> warms up for a couple of minutes it races up to 3000 rpm and stays there.
> Restarting doesn't help, and only when I unplug the idle control valve will
> it stop (die).
>
>
>
> I've checked the TPS with an ohm meter and it works fine, and the idle
> valve
> hums.  I can't find any vacuum leaks (propane torch probe), and it was
> recently tuned up.  So, is it possible for a bad Idle control unit to cause
> this?  It seems odd that an engine can run at 3000 with the throttle
> closed!
>
>
>
>
> The only way to test it is to replace it for $200.
>
>
>
> Thanks!
>
>
>
> Stuart
>