Is there a "best" cleaner for ISV?

Ben Swann bswann at
Mon Dec 16 11:52:07 EST 2002

I don't think that if you disconnected the ISV, and the idle dropped, that
means it is a bad ISV.  In fact, that tells me that the ISV is good, and
the control to the ISV is what is not working.  BTDT..I've fallen for this
trap too.

Look for problem with:
WOT(Idle) switch or circuitry.  Forget what else at the moment - brain
drizzle, but I've posted on this many times.. a whole lot of things not
necessarily ISV.

I don't know if I've encountered a good solution for cleaning - carb
cleaner seems to damage a marginal one making it bad.  Perhaps a good spray
lube can free up a sticking one.


[For the past week, I have been running my 87 5kcstq (267k miles) with the
ISV electrical pig tail disconnected. 100% success in eliminating high idle
(2,000+ RPM!)when coming down off a run, like at a toll booth, and only a
hint of problems when starting cold at 20 degree temperatures in the
morning. I just stay with it on the pedal for about a minute.

Haven't tried other cleaners because the weather is too cold to spend much
time outside messing about with such matters.

After the disconnect, I just used a small flat bladed screwdriver to touch
up the idle speed at the throttle body, so it idles hot at about 800-1000
RPM. This hot setting is a little low for cold start-ups, hence the need
for staying on the pedal at first.

Let me know if you find a magic bullet for the balky ISV. I tried cleaning
mine with carb solvent a few years ago and it helped for a short time.

Doyt Echelberger
Ohio   USA
At 09:01 AM 12/15/2002 -0500, you wrote:
>Cleaning the old ISV with carb cleaner spray resulting in stable idle for
>just a week or so. Anyone found a cleaner that works "best"?
>Mike Aiello
>87 5kcstq, 288k miles, orig. owner]

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