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Pulsing revs when engine cold

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Old Feb 24, 2020 | 10:36 PM
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Pulsing revs when engine cold

Starts fine when cold and I will immediately take off. About a second later when I am coming out of the parking lot rolling to a stop with the clutch pushed in, the engine will rev up and down several times. I will then come to the stop and it sounds like I am reving my engine up and down like I am trying to show off my exhaust. It does this for about 10 seconds and then stops. What would cause this?

Yes and before you ask I've cleaned the throttle bodies and have done the relearn procedure. I've also noticed when the engine is way when coming to a stop the revs will dip below ~600 and when idling warm it will feel like the whole car is vibrating. Please help!!
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Old Feb 24, 2020 | 10:38 PM
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Vacuum leak?
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Old Feb 24, 2020 | 11:01 PM
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Yea I'll have to look but I am not sure how a hose would disconnect if I hardly work on the engine other than regular maintenance
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Old Feb 24, 2020 | 11:11 PM
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I had an accord that did that same thing. It was a vacuum line I didn’t plug when I put on a CAI.
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Old Mar 6, 2020 | 09:21 PM
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I looked around the engine bay for some disconnected hoses and I dont see any, Of course hard for you guys to E-diagnose....but any other ideas
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Old Mar 7, 2020 | 10:00 AM
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Theres a few relearn procedures. One of them is TB reset. I believe another than causes issues if not done is idle volume relearn. Check out motorvate on youtube hes got vids on all of them
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Old Mar 8, 2020 | 01:26 PM
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Clean your maf sensors
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Old Mar 12, 2020 | 08:51 PM
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Thanks for the post, after reading it, I clean my MAFs with MAF cleaner and I feel it improved the overall health of my car. It doesn't buck when I am in a low pm about to fall out of gear and I can tell it doesn't struggle getting up to higher speeds on the higher way.

It didn't fix the pulsing revs issue but I am wondering if that it somehow caused by the friction of the spinning clutch on the flywheel after I push the clutch pedal down. I know there isn't much of a gap between the clutch and the flywheel so maybe when the engine is cold the spinning transmission is kinda running the engine.

I can live with the pulsing revs however I also needs to fix the intermittent lag when stepping on the gas under 3k rpms. There are some other threads on it and I think the brake pedal or systems has something to do with it
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