Throttle hang and the Idle Stepper Table
#317
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Here is my current understanding of the idle RPM, desired ISCV and the stepper table ...
When the car is in neutral or the clutch is depressed the car seems to go to the desired ISCV + an offset value (likely the stepper table value). If that doesn't reach the desired idle RPM the ECU adjust the stepper to reach the desired RPM.
If you are getting the bouncing idle you likely have the ISCV tables too high/low. If my assumption is correct and the using EvoKid's stepper table would require a higher desired ISCV than mine. So, if you tuned the ISCV for his table it would be too high for mine and cause idle issues.
When the car is in neutral or the clutch is depressed the car seems to go to the desired ISCV + an offset value (likely the stepper table value). If that doesn't reach the desired idle RPM the ECU adjust the stepper to reach the desired RPM.
If you are getting the bouncing idle you likely have the ISCV tables too high/low. If my assumption is correct and the using EvoKid's stepper table would require a higher desired ISCV than mine. So, if you tuned the ISCV for his table it would be too high for mine and cause idle issues.
#318
Evolved Member
iTrader: (47)
I started poking around the ISCV initial position tables and found that the one for neutral-AC On had the highest two cells raised double from the stock values which I believe could be why it would just hang around 2krpm. I changed those back to the stock values.
I'll toy around with it this evening.
I'm also looking forward to what you learn in your other idle thread.
Thanks for all your help.
I'll toy around with it this evening.
I'm also looking forward to what you learn in your other idle thread.
Thanks for all your help.
Last edited by biggie5252; Aug 1, 2008 at 04:24 PM.
#321
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I know I'll probably catch hell for not reading all 22 pages...but from the pages I did read some of you have the same problem I have but mine seems to be worse.
My 8 will actually not just hang or climb 400 RPM. My RPM will actually keep rising up to 2000 RPM. For all the smart @$$es...no my foot is not on the gas, no im not hitting the clutch before I get off the gas, nothing like that. Actually I can take my foot off the gas and put it flat on the floor while the RPM's climb. Like others, its not all the time. It happens even when not driving hard. I can be cruising on my way to work and shifting the car like you would if a cop is right next to you and BAMM! the RPM's shoot up 2000-2500.
My 8 will actually not just hang or climb 400 RPM. My RPM will actually keep rising up to 2000 RPM. For all the smart @$$es...no my foot is not on the gas, no im not hitting the clutch before I get off the gas, nothing like that. Actually I can take my foot off the gas and put it flat on the floor while the RPM's climb. Like others, its not all the time. It happens even when not driving hard. I can be cruising on my way to work and shifting the car like you would if a cop is right next to you and BAMM! the RPM's shoot up 2000-2500.
#323
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I don't idle at 2000...I'll be driving and when I go to shift from any gear to the next, lets say at 4500RPM, when I shift it will climb to 7000 RPM's. I even noticed one day I didn't take it out of gear, just put it in 3rd and got the RPM's to about 5000 and just took my foot off the gas and had both feet flat on the floor and it kept climbing like I still had my foot on the gas.
#324
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I can't stand this when driving my EVO. I'm willing to let a reputable shop take the car for troubleshooting, if they can fix it for me. I just want it fixed. Maybe Scott @ TTP needs to drive it and actually see whats happening to see what the deal may be.
#325
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I don't idle at 2000...I'll be driving and when I go to shift from any gear to the next, lets say at 4500RPM, when I shift it will climb to 7000 RPM's. I even noticed one day I didn't take it out of gear, just put it in 3rd and got the RPM's to about 5000 and just took my foot off the gas and had both feet flat on the floor and it kept climbing like I still had my foot on the gas.
#330
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I don't idle at 2000...I'll be driving and when I go to shift from any gear to the next, lets say at 4500RPM, when I shift it will climb to 7000 RPM's. I even noticed one day I didn't take it out of gear, just put it in 3rd and got the RPM's to about 5000 and just took my foot off the gas and had both feet flat on the floor and it kept climbing like I still had my foot on the gas.