Still trying to get my wife`s car to idle at a steady RPM. I must have a vacuum leak and I was wondering if anyone has ever worn out a throttle body on a CIS car?

If I start the car and set the mixture without touching the throttle, I can get a smooth 1000 rpm idle. But if I rev the car the idle will hang closer to 1400 rpm. If I adjust the mixture from 1400 to get it back to 1000 rpm, then it will run rough and not start without holding the throttle open. Air flow sensor height is correct. The low vacuum is making the mixture adjustment an on/off affair.

My problems all started after cleaning the throttle body with carb cleaner. I am hypothesizing that the crud was obstructing the air flow at idle and helping seal the throttle valve. I have removed/adjusted the throttle valve to insure that it is completely closed. It did have some wear marks on the sides of the bore, but this may be normal? All throttle switches are making contact.

Thoughts? Experiences?

Tinker

Hi,

Not sure if this helps, but is it possible you disloged something when cleaning the throtle body and now that something is obstructing fuel and or air flow? Inadequate fuel or air flow could result in eratic idle.

Joel

I have several used ones with over 250,000 miles on them & they show NO signs of wear!! IDLE problems on this engine are usually related to the AIR flow position sensor.

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