2003 Trailblazer wont idle with AC on

miketx

Diamond Member
Dec 25, 2015
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It's been doing this for about a month now and its got 230k miles on it. I knew I'd have to fix it so I looked on the internet. A gadzillion links come up explaining that all you need to do is clean the throttle body. I don't believe it. But, it is pretty easy to do so I tried it. Took it off and cleaned it with a wire brush some carb cleaner and blew it out with air real good. Put it back together and it started right up and idles smooth as silk with the AC on! Took less than an hour. I just don't see how I fixed it? It was gummy but no broke gasket, no clogged holes? Must have been just gummed enough to confuse the PCM and let it die when the AC demanded more.

Also I did not disconnect the battery like they all said and do the idle relearn procedure because I didn't want to have to relearn the rear blend actuator and the transmission. The PCM still tries to control it like it's still gummed up but it will relearn in about 15 miles of stop and start driving. Lucked out!
 

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