Car starts at full throttle

2008 CHEVROLET COBALT
194,000 MILES • 2.4L • 6 CYL • 2WD • AUTOMATIC
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GOTTAKEEPMOVIN'
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When I start the car, the car immediately revs up to approximately 3800 rpm's. No codes stored. Not sure what to do to get it to stop. I am tempted to say it may be throttle position sensor related, but not certain. Today I started the car again and it runs at 800 RPM without a problem. Still, no codes stored. Could be just me but it tends to act up when the car's been rained on.I am afraid this car is pretty much an undependable ride if I can't figure out what this intermittent issue is. Any hints or suggestions would be greatly appreciated! Thanks, in advance!
Oct 23, 2017 at 2:28 PM
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STRAILER
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It sounds like you have a larger vacuum leak or the throttle actuator is going out. Here is a couple guides to help you find and fix the problem.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

and

https://www.2carpros.com/articles/how-a-throttle-body-works

Sometimes when they go out it won't set a code but not very often.

Please let us know what happens.

Cheers, Ken
Oct 25, 2017 at 7:06 PM
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GOTTAKEEPMOVIN'
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After checking all vacuum lines, I decided to clean the throttle body as well as possible (albeit while still "on" the car) as much as possible. After having done that and driving the car for a couple of weeks to relearn the idle, the codes have not come back at all... Throttle body is clean and appears to be working properly at this point, so I will see how long it lasts... Thanks so much for the pointers!!
Nov 19, 2017 at 12:22 PM
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STRAILER
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Nice work, we are here to help, please use 2CarPros anytime.

Cheers, Ken
Nov 19, 2017 at 12:26 PM