prijedor

while upshifting over 3500 rpms or so and staying that high while driving with no foot on gas pedal.If i shut the car off rpms go back to normal and when shifting to higher gear at 2000-2500 rpms or so everything is normal also.Is this a case of bad ISV or something else?
My ISV is about 2-3 years old.Local parts store only has throttle body and air intake cleaner,is that ok to use for cleaning of ISV?
How exactly should i clean it?
Car in question is 1989 200quattro.

Number68

throttle body cleaner is safe to use on it, you want to spray some cleaner into it and then actuate the valve with a 9v battery a couple times, alternating which side you spray in until it drips out clear

MarkPan

Probably ISV. One time in winter the little dashpot damper deal under the throttle froze on me, and held the throttle open a bit...

Taking off from a stop at 4krpm all the way home, lol :-D

prijedor

Probably has nothing to do with this issue,but i have never replaced mi O2 sensor and i have owned car since 1996.MPG is at 18/25,has some hesitation when accelarating cold for first 2-3 minutes.
Any words of advice on replacing O2,looks like fairly straight forward job.
Is there 1 or 2 sensors on these cars?

type44

Just one, and it can cause some surging and hesitation, but wouldnt cause it to idle at 3k. If you replace it buy a bosch universal 3 wire and splice it onto your old connector, its much cheaper that way. I use plain old carb cleaner on my isv. Might also wanna check the elbows that connect to it, they tend to deteriorate pretty quick.