Poor Cold Idle (Yes I searched)
#212
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I got the 2K rev today. Once the car is warm...the rev never returned though. It acts like it is trying to find its idle by reving up to 2k then slowly back down to its setting.
When I set those ISCV settings, I had to re-adjust the BIS.
When I set those ISCV settings, I had to re-adjust the BIS.
#217
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The desired ISCV initial step position tables. Since my car was originally on 96530008 I input these ISCV values into my v7 rom. The car idles much smoother with no initial jump in RPM. I am on Revolver cams and have idle set at 1125 rpm. Any lower and the car is just too lopy for my taste.
AC off Neutral (I did raise the last entry...the 10...up from stock of 7)
145
126
116
116
93
68
17
10
AC off Drive
180
164
153
144
130
102
48
36
AC ON-Neutral
255
242
228
212
186
150
88
80
AC off Neutral (I did raise the last entry...the 10...up from stock of 7)
145
126
116
116
93
68
17
10
AC off Drive
180
164
153
144
130
102
48
36
AC ON-Neutral
255
242
228
212
186
150
88
80
https://www.evolutionm.net/forums/7634241-post69.html
#219
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I've been playing catch-up on this thread; has anyone found the root cause of the 2k-3k rpm spike on cold startup? It's SO annoying.
My car also has and idle problem during warm driving that I'm trying to get to the bottom of. First gear, medium acceleration, push clutch in and coast, rpms fall to ~500rpm, timing is at ~5° and then finally it catches itself and pulls back up to ~1000rpm idle. My biss screw seems frozen so I'm wondering if this is actually a hardware problem.
I went through and have enabled/disabled tons of settings, FAA bit 11 and the rest in that list. Got rid of my hole of -5's and tried several mixes of the cold timing % table before that. Does anyone know definitively what FAA Bit 10 (Timing Knockdown on Light Acceleration and less than <3000) actually does?
My car has been doing these little things for a long time, and I don't recall when. This thread has given me inspiration to try and solve all the 'little' problems. I've even switched to open loop idle, nothing seems to actually make problems go away...it may get better for one warmup cycle, get my hopes up, and then just return the next time. Very frustrating.
My car also has and idle problem during warm driving that I'm trying to get to the bottom of. First gear, medium acceleration, push clutch in and coast, rpms fall to ~500rpm, timing is at ~5° and then finally it catches itself and pulls back up to ~1000rpm idle. My biss screw seems frozen so I'm wondering if this is actually a hardware problem.
I went through and have enabled/disabled tons of settings, FAA bit 11 and the rest in that list. Got rid of my hole of -5's and tried several mixes of the cold timing % table before that. Does anyone know definitively what FAA Bit 10 (Timing Knockdown on Light Acceleration and less than <3000) actually does?
My car has been doing these little things for a long time, and I don't recall when. This thread has given me inspiration to try and solve all the 'little' problems. I've even switched to open loop idle, nothing seems to actually make problems go away...it may get better for one warmup cycle, get my hopes up, and then just return the next time. Very frustrating.
Last edited by scheides; Nov 6, 2009 at 10:54 AM.
#220
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The one thing that I changed that actually changed the 3000 RPM spike warm-up was zeroing out the percent low coolant temp timing trim, after I had already changed the hole of -5s and had been driving around like that for a week. For some reason it made my problems go away...
Scheides, I would suggest trying my settings since we both have 05's... just a suggestion...
Scheides, I would suggest trying my settings since we both have 05's... just a suggestion...
Last edited by Fast_Freddie; Nov 6, 2009 at 12:10 PM.
#221
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My car also has and idle problem during warm driving that I'm trying to get to the bottom of. First gear, medium acceleration, push clutch in and coast, rpms fall to ~500rpm, timing is at ~5° and then finally it catches itself and pulls back up to ~1000rpm idle. My biss screw seems frozen so I'm wondering if this is actually a hardware problem.
Those tables don't do what you think they do...
https://www.evolutionm.net/forums/7634241-post69.html
https://www.evolutionm.net/forums/7634241-post69.html
#222
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Frosty....please enlighten us with your knowlege of the ISCV tables then.
I ask becasue most certainly when I raised the values in the AC on ISCV table my stalling condition ceased.
I ask becasue most certainly when I raised the values in the AC on ISCV table my stalling condition ceased.
#223
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At this point, my cold start and cold idle are damn near perfect, even with E-85 and no EGR: the car fires on the first crank, no high-RPM warmup idle, no stalling post-cranking. My settings are basically the list that Fast_Freddie posted, minus the idle RPM changes and closed-loop trim control adjustments.
I still have a nasty low-throttle stumble during warmup, which I suspect is EGR-related; it has smoothed it out significantly from where I started (suggesting the other problems were simply aggravating it), but now I just need to spend a bit of time logging cold starts/drives.
----
scheides: looking at the code that checks FAA bit 10 (in 96530006, it looks like the code for that is at sub_17D62), I see a bunch of threshold tests. A flag (FFFF8A18 bit 0) is set if all of the following are true:
I'm running out of time right now to look at this, right now, but maybe this is enough for someone else to dig through it if they're motivated enough?
I still have a nasty low-throttle stumble during warmup, which I suspect is EGR-related; it has smoothed it out significantly from where I started (suggesting the other problems were simply aggravating it), but now I just need to spend a bit of time logging cold starts/drives.
----
scheides: looking at the code that checks FAA bit 10 (in 96530006, it looks like the code for that is at sub_17D62), I see a bunch of threshold tests. A flag (FFFF8A18 bit 0) is set if all of the following are true:
- RPM is between 3500 and 0 RPM (words at 17F6 and 17F8)
- coolant temp > 167F (word_19FA)
- vehicle speed frequency > 10Hz (word_19FA)
- a few bits in various locations in memory
- FFFF8A56 is between 0x178C and 0x16A (words at 17FA and 17FC); this is boost-related, but my disassembly is incomplete here. Someone want to fill me in?
- load error < 1.56 (word_24AC)
- vehicle is moving (speed > 6mph) (word_2C5C)
I'm running out of time right now to look at this, right now, but maybe this is enough for someone else to dig through it if they're motivated enough?
#224
Evolved Member
iTrader: (50)
At this point, my cold start and cold idle are damn near perfect, even with E-85 and no EGR: the car fires on the first crank, no high-RPM warmup idle, no stalling post-cranking. My settings are basically the list that Fast_Freddie posted, minus the idle RPM changes and closed-loop trim control adjustments.
I still have a nasty low-throttle stumble during warmup, which I suspect is EGR-related; it has smoothed it out significantly from where I started (suggesting the other problems were simply aggravating it), but now I just need to spend a bit of time logging cold starts/drives.
----
scheides: looking at the code that checks FAA bit 10 (in 96530006, it looks like the code for that is at sub_17D62), I see a bunch of threshold tests. A flag (FFFF8A18 bit 0) is set if all of the following are true:
I'm running out of time right now to look at this, right now, but maybe this is enough for someone else to dig through it if they're motivated enough?
I still have a nasty low-throttle stumble during warmup, which I suspect is EGR-related; it has smoothed it out significantly from where I started (suggesting the other problems were simply aggravating it), but now I just need to spend a bit of time logging cold starts/drives.
----
scheides: looking at the code that checks FAA bit 10 (in 96530006, it looks like the code for that is at sub_17D62), I see a bunch of threshold tests. A flag (FFFF8A18 bit 0) is set if all of the following are true:
- RPM is between 3500 and 0 RPM (words at 17F6 and 17F8)
- coolant temp > 167F (word_19FA)
- vehicle speed frequency > 10Hz (word_19FA)
- a few bits in various locations in memory
- FFFF8A56 is between 0x178C and 0x16A (words at 17FA and 17FC); this is boost-related, but my disassembly is incomplete here. Someone want to fill me in?
- load error < 1.56 (word_24AC)
- vehicle is moving (speed > 6mph) (word_2C5C)
I'm running out of time right now to look at this, right now, but maybe this is enough for someone else to dig through it if they're motivated enough?