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Old 06-10-2016, 04:57 PM   #1
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Default Idle jump with car in gear and clutch pedal still pressed in

Figured i'd just ask, my idle will jump to 2500 rpm if i put it in any gear with the clutch pedal still pressed down. I haven't touched the idle controls, just the idle cells for fuel and the warm up enrichment. I can't seem to find any solid answer on this, some have said maybe the clutch switch? Anyways, anyone could point me in t he right direction it would be much appreciated!
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Old 06-10-2016, 07:36 PM   #2
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You can play with the clutch switch independently of the clutch pedal. It's a small white plastic box behind the pedal arm. Start there to isolate whether it's an issue with the electronics or mechanicals. I can't think of an obvious reason why you're experiencing those symptoms, but that test should help steer your investigation.
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Old 06-10-2016, 07:56 PM   #3
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Reading up a little bit, I see there are two idle switches: the one behind the clutch pedal, and one in the transmission. They tell the ECU to enter IAC control and idle timing. I'd guess you have a good sensor in the transmission, but a bad one under the pedal. Your trans sensor is telling your ECU to enter idle timing when you're in neutral, but when you push in the clutch pedal and row it into gear, the pedal sensor isn't telling the ECU to stay in idle timing. Watch your timing map as you shift between neutral & a gear with the clutch pushed in. Does it jump?

Pure conjecture. I've never dealt with this problem...
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Old 06-10-2016, 08:21 PM   #4
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I loaded up my tune and went out, every time i go into gear the timing does jump up. When i let the clutch out while the car is in gear it will just take off and accelerate on it's own until it reaches the 2500 rpm..very odd.
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Old 06-10-2016, 08:24 PM   #5
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Activating launch control?
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Old 06-10-2016, 08:25 PM   #6
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Launch control is disabled.
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Old 06-10-2016, 08:40 PM   #7
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More on this . I loaded the base map to see if i did something tune wise, but the car acts the same with a higher idle.
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Old 06-10-2016, 08:56 PM   #8
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Uh, is this a new tune? You gotta fiddle with your IAC PWM settings, and maybe even your idle valve screw.
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Old 06-10-2016, 08:59 PM   #9
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The tune is not new, I had it on the road and driving around, then i started adjusting the AE and warmup settings. Same day this started.
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Old 06-10-2016, 09:11 PM   #10
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Variable tps or OEM?
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Old 06-10-2016, 09:15 PM   #11
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oem TPS
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Old 06-10-2016, 09:18 PM   #12
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After you getting ae events at idle?
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Old 06-10-2016, 09:21 PM   #13
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No AE is being triggered at idle. When i put the car into gear i can hear the idle valve get much louder then the engine revs up. my laptop is currently charging, maybe ill upload my tune in a few.
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Old 06-10-2016, 09:27 PM   #14
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Here it is, it's a massive work in progress. most has been done with auto tune.
Attached Files
File Type: msq CurrentTune.msq (107.8 KB, 36 views)
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Old 06-11-2016, 01:44 PM   #15
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Alrighty, quick update - i jumped the clutch switch to bypass the rod activated by the pedal. Same problem. Since the car acts the same regardless if i load an old tune way back before this was an issue, i am assuming something else is at play here.
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Old 06-11-2016, 02:28 PM   #16
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OK, so just to keep troubleshooting, i re-installed the factory ecu, and afm.. no problems..so the issue is either with all my tunes or the ecu.
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Old 06-11-2016, 03:05 PM   #17
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Map sensor issue?
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Old 06-11-2016, 03:10 PM   #18
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MAP sensor appears to be functioning fine, it sits where it always has at idle and moves around when i drive.
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Old 06-11-2016, 03:43 PM   #19
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i dont know if this is relivent to your issue or not but my rx-8 used to idle jump between 800 and 2500 over and over then when i pressed the clutch it stopped

now i dont know if this fault can cause other symptoms or not but it was the neutral position sensor in my gear box one of the connectors had vibrated off but you got simlar symptoms when they start to fail as well so its just an idea you might want to try there are 2 sensors usually in the gear box i think 1 is the reverse sensor and 1 is the neutral sensor but that may differ on gearbox models im not sure but i think its a good idea just to check them
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Old 06-11-2016, 04:09 PM   #20
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Quote:
Originally Posted by nomic View Post
i dont know if this is relivent to your issue or not but my rx-8 used to idle jump between 800 and 2500 over and over then when i pressed the clutch it stopped

now i dont know if this fault can cause other symptoms or not but it was the neutral position sensor in my gear box one of the connectors had vibrated off but you got simlar symptoms when they start to fail as well so its just an idea you might want to try there are 2 sensors usually in the gear box i think 1 is the reverse sensor and 1 is the neutral sensor but that may differ on gearbox models im not sure but i think its a good idea just to check them
Thanks for the info, i'll look into that. Not sure it will be the cause since the problem goes away with the factory ecu..but i'll try anything.
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