Has anyone turned off Throttle Cracker, and 2nd...why does my idle timing jump around
08-09-2004, 07:42 PM
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Has anyone turned off Throttle Cracker, and 2nd...why does my idle timing jump around Has anyone disabled throttle cracker...if so, what were the results? And why does timing jump around at idle. I checked all the tables I can edit, and they all have the same timing or modifiers...is there a table I need access to in HPTuners that I don't have? I don't see why it would fluctuate between 22.5 and 25.5 at idle. Thanks.
08-10-2004, 08:19 AM
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Originally Posted by Another_User
Has anyone disabled throttle cracker...if so, what were the results? And why does timing jump around at idle. I checked all the tables I can edit, and they all have the same timing or modifiers...is there a table I need access to in HPTuners that I don't have? I don't see why it would fluctuate between 22.5 and 25.5 at idle. Thanks.
The throttle cracker enable/disable speeds control when the PCM transitions in and out of the adaptive idle routines that control the IAC motor. ie. below the speed threshold adaptive idle will run, above the threshold it is disabled.
Hope that helps,
Chris...
08-10-2004, 06:42 PM
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ECM programs are stupid. What kind of moron makes the timing adjust the idle speed too. Basically, the IAC starts playing with itself and fidgeting around, so the timing starts to change to in order to change the idle speed. So the engine picks up vacuum, the computer says "woohoo, time to adjust the IAC again!" and so on, and so on. No wonder fuel injected cars act so retarded. These cars would run awesome if you could tell them to cut with the damn fidgeting.
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08-10-2004, 08:26 PM
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Actually, I was thinking about zeroing out my throttle cracker and idle IAC settings and manually setting my throttle body to the desired rpm, and then disabling whatever codes pop up...comments anyone? Am I just opening myself up for a big pain in the buttox?
08-10-2004, 08:49 PM
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well the IAC does more than just control the static idle speed, it provides you a temperature based Idle RPM control, a startup throttle function, it also controls off-idle RPM (throttle cracker), return to idle (throttle follower), stall saver functions, airflow compensation when you turn the AC on, the fans come on, put the trans in gear etc.
What exactly is the problem?
What exactly is the problem?
08-10-2004, 08:53 PM
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The normal slight surging, etc. I just like tinkering, and I noticed that the PCM is out of it's mind. But I am also seeing a difference on my cruice IAC counts from 10 desired to 90s actual. I was just thinking about trying an old-school approach to tuning idle and cruise I guess.
08-10-2004, 09:18 PM
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Originally Posted by marc_w
My truck used to jump about 10* stock... now with the little cam in there, it's anywhere from 6 degrees to mid 20's. 
08-10-2004, 09:40 PM
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Yeah, idle timing...
Here's the truck idling... ...granted, it looks like it's "only" going from 11 to lower 20's there.
Like I said, it's pretty much done that stock. With the cam (TR220 112) and my shoddy tuning, the idle is erratic at times. That's where I see timing dip as low as 6*.
I'm also on a drive by wire TB, so that might make a difference. I have no control over that throttle blade.
Here's the truck idling... ...granted, it looks like it's "only" going from 11 to lower 20's there.
Like I said, it's pretty much done that stock. With the cam (TR220 112) and my shoddy tuning, the idle is erratic at times. That's where I see timing dip as low as 6*.
I'm also on a drive by wire TB, so that might make a difference. I have no control over that throttle blade.
08-10-2004, 11:49 PM
#15
Try changing your main spark table selects threshold. Maybe it's fluctuating between the main and idle spark tables for some reason. Are your idle spark tables stock cause all the cells that would apply to idle have 22 degrees in them. I don't know where it'd get 25 degrees, especially since all the correction tables subtract timing, not add it. Except the egr table and ect correction.
08-11-2004, 04:14 AM
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Originally Posted by marc_w
Yeah, idle timing...
Here's the truck idling... ...granted, it looks like it's "only" going from 11 to lower 20's there.
Like I said, it's pretty much done that stock. With the cam (TR220 112) and my shoddy tuning, the idle is erratic at times. That's where I see timing dip as low as 6*.
I'm also on a drive by wire TB, so that might make a difference. I have no control over that throttle blade.
Here's the truck idling... ...granted, it looks like it's "only" going from 11 to lower 20's there.
Like I said, it's pretty much done that stock. With the cam (TR220 112) and my shoddy tuning, the idle is erratic at times. That's where I see timing dip as low as 6*.
I'm also on a drive by wire TB, so that might make a difference. I have no control over that throttle blade.
08-11-2004, 09:43 AM
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Originally Posted by HumpinSS
On the drive by wire vehicles you do have control over it using the Air flow idle table
I've been logging my "Idle Airflow Desired" when I do any idle changes. In P/N, it's around the 7 g/cyl range - which is "close" to what my stock tables says. IAC's are 60-70.
In gear, IAD is up in the 10-11 g/cyl range - while my stock table is in the 6's. I bumped the stock table up to 10, and I get major CCE. IAC's are 130 or so, either way.
08-11-2004, 09:46 AM
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P Mack... good call... I'm running bone-stock maps right now, all around. My stock "Main Spark Table Selects" are as follows:
%TPS 1.2
Hysteresis 0.7
Speed 255
Hysteresis 1.0
%TPS 1.2
Hysteresis 0.7
Speed 255
Hysteresis 1.0
08-11-2004, 12:49 PM
#19
Originally Posted by marc_w
In gear, IAD is up in the 10-11 g/cyl range - while my stock table is in the 6's. I bumped the stock table up to 10, and I get major CCE. IAC's are 130 or so, either way.
08-11-2004, 04:34 PM
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Originally Posted by Bink
What table is this in HP Tuners....an Idle Air in Gear table??? Not a In Gear decay table???