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Discussion Starter #1
Yesterday on the highway I was going downhill, with my cruise control on. All of the sudden, the car accelerates heavily to around 3500rpm, then dips and gets stuck at around 3100rpm. My speed increased briefly, but not by a whole lot. I turn the cruise control off, slow it down but still the car is running a high rpm. Even with my foot off the gas, cruise control off, and the car just rolling, the rpm was "stuck" around 3100. I pull over, stop the car, remove the key from the ignition. Turn it over, and get going on and try for cruise control again. The same thing happened a few minutes later.

Does anyone have any clue what this could be? The rest of the trip I drove without cruise control and had zero problems whatsoever.
 

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Old Phart
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The car listed in your profile is a 2009, making this an interesting question since the throttle is electronically controlled.

One question, you didn't mention what transmission or RPM at cruising speed, needed to try & answer all questions.
 

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Discussion Starter #3
It's an automatic. RPM at cruising I believe is around 2000. It tends to have a high idle when I start it up, but that has gone on for years now.
 

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Old Phart
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Something odd, like dropping out of gear, since if IN gear it couldn't just idle along at the same speed with RPM at 3100 vs. prev. 2000 cruising.

I asked cruising RPM at that speed to compare with what you had after disengagement of the cruise control - should stay similar in gear manual or automatic.
 

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Discussion Starter #7
It felt as if I shifted gears too early (if my car were manual).

Yeah once I took it out of cruise control, it just locked me up around 3100. I pulled over on the side of the highway to stop the car and as I crossed the rumble strips (probably going around 20mph), it still was way high.
 

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I'm also having trouble understanding how cruise can hang at 3100 or 3500 without car being at 70 mph or so. And that would be 3rd gear, in OD you'd be at 100 mph. Is OP saying he drives around using cruise in lower gears????

Part of that based on this...................

'My speed increased briefly, but not by a whole lot.'

'RPM at cruising I believe is around 2000.'

Even 3100 rpm is an increase in speed of 50%, that is NOT a little.

OP is obviously confused.

'It felt as if I shifted gears too early (if my car were manual).'

That would be the exact opposite of what he seems to be trying to describe. Rpm DROPS there rather than increasing.

With electronic TB I say take it to a shop, OP doesn't need to be messing with it.
 

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Discussion Starter #9
Cruise control was on when I was going around 62. The jump brought the car up to around 77, then settled down at 72ish, with the RPM up to 3500, then settling at 3100, even as I pulled the car over. It only went down below 3k when the car was in park.

I haven't messed with it. I just don't use cruise control any more. That solved the problem.

Sorry for any confusion.
 

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More like it..................this threw us off............

'My speed increased briefly, but not by a whole lot.'
 
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