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Discussion Starter · #1 · (Edited)
Hey all, first small hiccup ownership here, I suppose. Sometimes when I disengage the clutch, the revs dip slightly. It only happens when Im slowing down to a stop. I depress the clutch so I can shift into neutral, and the revs dip below 700 but then quickly come back up to regular idle. Its very intermittent, I cant reproduce the issue at will.

The car idles just fine, around 700 steady. I used to have a small rough idle issue with the car but I cleaned the MAF when I put in the snabb intake.

Could this be a vacuum issue? The car has never stalled on me and I never let the car shudder or choke when engaging/disengaging the clutch.

Thanks in advance.

EDIT: Issue solved. Answer in thread.
 

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Could also be the clutch pedal sensor too. ECU tries to compensate for whether its engaging or disengaging, so once its starts going bad it can cause strange throttle like issues too.
 

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Discussion Starter · #3 ·
Shifting isnt at all jerky and cruise control works fine. Does this mean the CPS can be ruled out?
 

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Shifting isnt at all jerky and cruise control works fine. Does this mean the CPS can be ruled out?
No. Things can fail intermittently. Anything showing up in VIDA?
 

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No, because since its intermittent its working most of the time, so the cruise working isn't really telling you anything one way or the other.

Assuming your throwout bearing isn't going to ****, that sensor should be the only reason your idle is bouncing around when you use the clutch.
 

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Discussion Starter · #6 · (Edited)
Id imagine the throwout bearing is fine, only 34k miles on it, but no way to know for sure I suppose. I havent had it scanned yet, I should invest. So stealthy, you dont suspect a vacuum issue, maybe when I installed the intake? Wasnt happening before then, but didnt happen immediately after I installed it either.

EDIT: do you think there would be a code corresponding to the cps if this was the culprit?
 

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I have the same issue. Sometimes (maybe 1 in 15) When I come to a stop my idle drops 100 ir so RPM but then picks back up right away. Ive played with it a little and i dont thibk the clutch pedal is what is causing it, if I place it in nutral and coast the a stop without pressing the clutch the same thing will happen. I've checked for vacume leaks and have none. Ive decided unless it gets worse im not going to worry about it that much.
 

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A dirty/bad throttle body could be the culprit as well.

A/C on or off? Sometimes if it's timed just right, the compressor can kick on while the revs are falling, causing it to drop below where it should be for a second.
 

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There may be other causes, including a leak in the system. Then again a leak bad enough to throw off your idle should be throwing codes at boost when the MAF senses that more air is going into the turbo than the engine can really be consuming.

Could also be a FPS or throttle body issue, so a vida scan wouldn't be a bad way to narrow down the possibilities instead of completely guessing.
 

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Discussion Starter · #10 ·
Righto. Im going to try and get it scanned by the end of the week and come back with what I find.
 

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Discussion Starter · #11 ·
So I scanned it with VIDA/DiCE, no codes. Any guesses as to what this could be a precursor to?
 

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Discussion Starter · #14 ·
If you have dice have you run a check of the TB to make sure its good? If so then I would look closer at the clutch pedal sensor.
So I dont think i can run a check of the TB on my year car with vida/dice, I havent looked at the cps physically yet but I dont even think that is whats causing it anymore. Its only when the car comes to a stop, even if I place it in neutral while coasting. I'm totally stumped.
 

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So I dont think i can run a check of the TB on my year car with vida/dice, I havent looked at the cps physically yet but I dont even think that is whats causing it anymore. Its only when the car comes to a stop, even if I place it in neutral while coasting. I'm totally stumped.
Exactly the same as mine. If you ever figure it out let me know.
 

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Discussion Starter · #16 · (Edited)
Exactly the same as mine. If you ever figure it out let me know.
And vice versa my friend lol. Very irritating. I'm going to check my cps when I have time but I doubt the module is broken or deformed in any way.

I'll be updating this thread if I find anything. I'll certainly be investigating.
 

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There are different maps for idle torque depending on clutch engaged or disengaged. Could be very well be it. It just takes a moment for the idle to stabilize.
 

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Discussion Starter · #18 ·
So I'm back to chasing this lol. I was searching through threads and I forgot I made this one. Contrast, I took your last post and just lived with it for a while assuming it was that.

But it seems to be happening a bit more frequently now. STILL no codes. Would cleaning the TB really solve this? Pretty sure it's never been cleaned. Or am I just asking for trouble at this point? Got 44k on the clock now.
 

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So I'm back to chasing this lol. I was searching through threads and I forgot I made this one. Contrast, I took your last post and just lived with it for a while assuming it was that.

But it seems to be happening a bit more frequently now. STILL no codes. Would cleaning the TB really solve this? Pretty sure it's never been cleaned. Or am I just asking for trouble at this point? Got 44k on the clock now.
I completely swapped out my TB and it didn't change. I just recently did my PVC (with TB and intake spacer from Viva), new turbo, and new exhaust system and it seems to have gotten way better. It has only happened one or two times since that work almost a month ago and my R is my daily driver. Not sure what made it better as I did all 3 at the same time, im thinking it might be a very small vacume leak that I fixed while doing all of that?
 

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Discussion Starter · #20 ·
I completely swapped out my TB and it didn't change. I just recently did my PVC (with TB and intake spacer from Viva), new turbo, and new exhaust system and it seems to have gotten way better. It has only happened one or two times since that work almost a month ago and my R is my daily driver. Not sure what made it better as I did all 3 at the same time, im thinking it might be a very small vacume leak that I fixed while doing all of that?
Mendo, do you have engine mounts or bracing that you removed or replaced recently? I read something on here saying that stiffening the engine up and preventing it from moving can precipitate this issue sometimes...but not sure how that could be it since it's only when coasting to a stop.
 
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