Idle jump with car in gear and clutch pedal still pressed in
06-10-2016, 03:57 PM
#1
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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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06-10-2016, 06:36 PM
#2
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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06-10-2016, 06:56 PM
#3
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...
Pure conjecture. I've never dealt with this problem...
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06-10-2016, 07:21 PM
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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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06-10-2016, 08:21 PM
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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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06-11-2016, 12:44 PM
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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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06-11-2016, 02:43 PM
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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
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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06-11-2016, 03:09 PM
#20
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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
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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