Idle fluctuation?
#1
Idle fluctuation?
So today I replaced my clutch slave cylinder and clutch master cylinder. I took off the UIM to get to the slave and also cleaned my throttle body while it was off. After putting everything back together my clutch was fine and car started normally it also idles fine. But one problem as soon as I put the car in gear with the clutch down the idle bounces from almost exactly 1000rpm to 1500rpm and keeps bouncing until I either drive or take it out of gear. It drives in all gears fine and idles out of gear fine until I put it in gear with the clutch down, which is when it fluctuates from 1k-1500rpm.
I was thinking it could be a problem with my throttle body but reading up on here i'm also hearing it could be the neutral safety switch? I've never had this problem until now. Could it be that the switch is dirty from when I was replacing the slave? I know the neutral safety switch is around the same area of the transmission as the slave. Should I try cleaning it or replace it? It's weird that the idle fluctuations are almost exactly going from 1k to 1.5k though.
I was thinking it could be a problem with my throttle body but reading up on here i'm also hearing it could be the neutral safety switch? I've never had this problem until now. Could it be that the switch is dirty from when I was replacing the slave? I know the neutral safety switch is around the same area of the transmission as the slave. Should I try cleaning it or replace it? It's weird that the idle fluctuations are almost exactly going from 1k to 1.5k though.
#3
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If it's a fairly precise idle bounce, then yes, it sounds like the neutral switch. One way to know for sure is to do an OBD2 code check for pending codes. It will take 3-ish drive cycles before you will get a lit CEL for the neutral switch.
Considering that you have to remove the clutch pedal to replace the clutch master, and to remove the clutch pedal you have to disconnect a switch on the clutch pedal that is in the neutral switch circuit...
...are you sure you plugged that switch's electrical connector back in?
The neutral switch itself is below the shifter, inside the transmission turret, so unless you disconnected that wiring, you probably didn't do anything that affected it there.
Considering that you have to remove the clutch pedal to replace the clutch master, and to remove the clutch pedal you have to disconnect a switch on the clutch pedal that is in the neutral switch circuit...
...are you sure you plugged that switch's electrical connector back in?
The neutral switch itself is below the shifter, inside the transmission turret, so unless you disconnected that wiring, you probably didn't do anything that affected it there.
#4
If it's a fairly precise idle bounce, then yes, it sounds like the neutral switch. One way to know for sure is to do an OBD2 code check for pending codes. It will take 3-ish drive cycles before you will get a lit CEL for the neutral switch.
Considering that you have to remove the clutch pedal to replace the clutch master, and to remove the clutch pedal you have to disconnect a switch on the clutch pedal that is in the neutral switch circuit...
...are you sure you plugged that switch's electrical connector back in?
The neutral switch itself is below the shifter, inside the transmission turret, so unless you disconnected that wiring, you probably didn't do anything that affected it there.
Considering that you have to remove the clutch pedal to replace the clutch master, and to remove the clutch pedal you have to disconnect a switch on the clutch pedal that is in the neutral switch circuit...
...are you sure you plugged that switch's electrical connector back in?
The neutral switch itself is below the shifter, inside the transmission turret, so unless you disconnected that wiring, you probably didn't do anything that affected it there.
#6
I checked the connections and they look fine. although the one to the left that needs to be turned to remove. I'm not too sure if thats the exact position it was in before. I'm kinda stumped. I'm gonna try to maybe clean them tomorrow and scan for any pending codes. I'm really hoping its not the neutral safety switch itself. Looks like a PITA to change. being all the way on top of the tranny.
#8
So I got a CEL this morning and pulled the codes. Got a P0704 and p0410. 704 I'm guessing was for the connector under the clutch pedal? I have yet to re check the connectors. but will soon. 410 is the air pump. I'm wondering if when I took off the UIM if I put back the vacuum hoses for the air pump back correctly. I think I did because I have no vacuum issues at idle or while driving. Any suggestions?
#9
Bump... anyone know anything related to P0704.. checked all the switches/connectors under my clutch pedal and they seem connected fine. The code reads CPP sensor (clutch pedal position). Is there a certain way the sensor should face? Or should I just replace the sensor under the pedal?
I'm only getting a idle fluctuation when the car is in gear with the clutch down. It moves from 1k-1500rpm and keeps fluctuating until I drive or take it out of gear.
I'm only getting a idle fluctuation when the car is in gear with the clutch down. It moves from 1k-1500rpm and keeps fluctuating until I drive or take it out of gear.
#10
Super Moderator
DTC P0704
CPP switch input circuit problem
DETECTION CONDITION
The PCM monitors the input signal from the CPP switch when the vehicle speed is more than 30 km/h {19 mph}. If the input signal does not change while alternately accelerating and decelerating 10 times, the PCM determines that there is a CPP switch input circuit malfunction.
Diagnostic support note
This is a continuous monitor (CCM).
The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
The DTC is stored in the PCM memory.
POSSIBLE CAUSE
CPP switch malfunction
Connector or terminal malfunction
Open circuit in wiring harness between CPP switch terminal B and PCM terminal 4F
Short to ground in wiring harness between CPP switch terminal B and PCM terminal 4F
Open circuit in wiring harness between CPP switch terminal D and ground
PCM malfunction
CPP switch input circuit problem
DETECTION CONDITION
The PCM monitors the input signal from the CPP switch when the vehicle speed is more than 30 km/h {19 mph}. If the input signal does not change while alternately accelerating and decelerating 10 times, the PCM determines that there is a CPP switch input circuit malfunction.
Diagnostic support note
This is a continuous monitor (CCM).
The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
The DTC is stored in the PCM memory.
POSSIBLE CAUSE
CPP switch malfunction
Connector or terminal malfunction
Open circuit in wiring harness between CPP switch terminal B and PCM terminal 4F
Short to ground in wiring harness between CPP switch terminal B and PCM terminal 4F
Open circuit in wiring harness between CPP switch terminal D and ground
PCM malfunction
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sharingan 19 (04-29-2020)
#12
UPDATE: Issue resolved. I installed the new CPP switch under the clutch pedal (insert and rotate clockwise) I realized it actually clicked or snapped in place? Rather than the old one which felt loose. No more idle bounce/surge. Car runs mint and holds a strong idle now. Also adjusted the clutch and feels strong. Now just to order the reinforced bracket or get mines welded as preventative maintenance is my next decision.
#15
Hey guys, Sorry to bring up an older thread but this was the closest one I could find to my current problem.
I started getting the P0704 code about a week ago after attempting to teach the GF how to drive stick (Probably could have picked a better car for that) After many stalls, rough starts etc I ran my OBDII to clear the Cat code and noticed the P0704. Checked the switches yesterday and noticed the switch for the Neutral Switch circuit wasn't attached to the metal bracket.
Got the Switch attached to the bracket and all of a sudden I had cruise for the first time! But. the idle also surges back and forth to ~1k and back. Should I be looking into getting the neutral safety switch or the clutch position sensor? Is having it unattached from the clutch assembly hurting my performance?
Thanks for any help
I started getting the P0704 code about a week ago after attempting to teach the GF how to drive stick (Probably could have picked a better car for that) After many stalls, rough starts etc I ran my OBDII to clear the Cat code and noticed the P0704. Checked the switches yesterday and noticed the switch for the Neutral Switch circuit wasn't attached to the metal bracket.
Got the Switch attached to the bracket and all of a sudden I had cruise for the first time! But. the idle also surges back and forth to ~1k and back. Should I be looking into getting the neutral safety switch or the clutch position sensor? Is having it unattached from the clutch assembly hurting my performance?
Thanks for any help
#16
Hey guys, Sorry to bring up an older thread but this was the closest one I could find to my current problem.
I started getting the P0704 code about a week ago after attempting to teach the GF how to drive stick (Probably could have picked a better car for that) After many stalls, rough starts etc I ran my OBDII to clear the Cat code and noticed the P0704. Checked the switches yesterday and noticed the switch for the Neutral Switch circuit wasn't attached to the metal bracket.
Got the Switch attached to the bracket and all of a sudden I had cruise for the first time! But. the idle also surges back and forth to ~1k and back. Should I be looking into getting the neutral safety switch or the clutch position sensor? Is having it unattached from the clutch assembly hurting my performance?
Thanks for any help
I started getting the P0704 code about a week ago after attempting to teach the GF how to drive stick (Probably could have picked a better car for that) After many stalls, rough starts etc I ran my OBDII to clear the Cat code and noticed the P0704. Checked the switches yesterday and noticed the switch for the Neutral Switch circuit wasn't attached to the metal bracket.
Got the Switch attached to the bracket and all of a sudden I had cruise for the first time! But. the idle also surges back and forth to ~1k and back. Should I be looking into getting the neutral safety switch or the clutch position sensor? Is having it unattached from the clutch assembly hurting my performance?
Thanks for any help
#17
Hey guys, I am having some idling issues when the car is in neutral. It does not do it all the time and seems to only do it shortly after a cold start. When sitting in neutral the RPMs jump from 1000 to 1500 rpms and it continues to do it until either I press the clutch or rev up the engine. Once I rev up or put the car in gear it does not do it again.
Any help, tips, direction will be appreciated.
Thanks!
2006 Mazda RX-8 Shinka 53K
Any help, tips, direction will be appreciated.
Thanks!
2006 Mazda RX-8 Shinka 53K
#18
Out of NYC
iTrader: (1)
Hey guys, I am having some idling issues when the car is in neutral. It does not do it all the time and seems to only do it shortly after a cold start. When sitting in neutral the RPMs jump from 1000 to 1500 rpms and it continues to do it until either I press the clutch or rev up the engine. Once I rev up or put the car in gear it does not do it again.
Any help, tips, direction will be appreciated.
Thanks!
2006 Mazda RX-8 Shinka 53K
Any help, tips, direction will be appreciated.
Thanks!
2006 Mazda RX-8 Shinka 53K
#19
Thanks!
#20
Out of NYC
iTrader: (1)
Is it hard? Well if it's really that switch, it's located almost to the top of the tranny on the side. It's not exactly hard to get to it if u know what to look for and how to position ur arm.
#21
If it does this every time u start ur car, u should get a cel after 3 times, or if u have a code reader u might be able to get a pending code, just to give u a better idea if it's really failing
Is it hard? Well if it's really that switch, it's located almost to the top of the tranny on the side. It's not exactly hard to get to it if u know what to look for and how to position ur arm.
Is it hard? Well if it's really that switch, it's located almost to the top of the tranny on the side. It's not exactly hard to get to it if u know what to look for and how to position ur arm.
Thanks!
#22
Had the same problem with the idle fluctuation or cycling from 1000 to 1500 when in gear but perfect idle when in neutral (6 speed trans). Found the plunger was not fully releasing on CPP switch on the clutch pedal. The switch was coming apart which was causing the plunger to stick. A small tie wrap around the switch now holds it together and the plunger fully releases as the pedal is pushed down. Idle now is steady at 900 ish rpm.
#23
I have an 04, and mine is doing the same thing. It idles fine in neutral, but bounces from .9-1.5k when in first. I just replaced my CPP but it's still fluctuating. Anything else I should check?
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