"I just replaced my torque converter now it unlocks randomly" FIX
08-09-2004, 02:52 AM
#21
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Originally Posted by Ryan Karasek
Ok, I hear this issue all the time, its time for a sticky.
Guys/Gals with automatic cars listen up!
When you switch to a nice high stall torqe converter, the PCM can no longer use its default program to determine engine misfire. Here is the reason: The corque converter is part of the rotating mass of the engine's rotating assembly. When you reduce the wieght of the converter you are reducing the amount of Flywheel effect. The computer's stock tune is very sensitive to this rotating mass. Therefore the computer can no longer accuratly read engine misfire.
The computer has a logic routine that has certain perameters to be met before the computer locks the TC. They are (as far as I can tell):
1. Throttle position vs. MPH (normal cruise tables)
2. Engine coolant temperature > ???F (not accessable in edit)
3. > 40-50 misfires per 200 revolutions (not accessable in edit)
4. TPS = WOT
After these parameters are met, the computer waits 4-5 seconds then locks the converter.
So, for this thread the number three is the issue. Now keep in mind this is NOT code based. If you disable code PO300, this problem still exists, cause it is only looking at the current misfire count. there are only two ways (in Edit) to prevent these faulse misfires from affecting the TC lockup:
1. Set the misfire activation temperatures to 141 and deactivaion temps to 142. This is the easiest method, but its drawback is the complete disabling of the misfire detection/trouble shooting.
2. This method is more trial and error, it involves adusting the time delays of the misfire program in edit for the various ranges of detection. I personally don't use this method, so someone who does feel free to chime in here.
After disabling the misfire detection, barring any mechanical failures, the person should have little to no issues with TC lockup. I hope this helps, please feel free to direct people to this thread if you see they are haveing a TC lock up issue after installing a new torque converter.
Ryan K.
LS1 Edit Beta Tester
Guys/Gals with automatic cars listen up!
When you switch to a nice high stall torqe converter, the PCM can no longer use its default program to determine engine misfire. Here is the reason: The corque converter is part of the rotating mass of the engine's rotating assembly. When you reduce the wieght of the converter you are reducing the amount of Flywheel effect. The computer's stock tune is very sensitive to this rotating mass. Therefore the computer can no longer accuratly read engine misfire.
The computer has a logic routine that has certain perameters to be met before the computer locks the TC. They are (as far as I can tell):
1. Throttle position vs. MPH (normal cruise tables)
2. Engine coolant temperature > ???F (not accessable in edit)
3. > 40-50 misfires per 200 revolutions (not accessable in edit)
4. TPS = WOT
After these parameters are met, the computer waits 4-5 seconds then locks the converter.
So, for this thread the number three is the issue. Now keep in mind this is NOT code based. If you disable code PO300, this problem still exists, cause it is only looking at the current misfire count. there are only two ways (in Edit) to prevent these faulse misfires from affecting the TC lockup:
1. Set the misfire activation temperatures to 141 and deactivaion temps to 142. This is the easiest method, but its drawback is the complete disabling of the misfire detection/trouble shooting.
2. This method is more trial and error, it involves adusting the time delays of the misfire program in edit for the various ranges of detection. I personally don't use this method, so someone who does feel free to chime in here.
After disabling the misfire detection, barring any mechanical failures, the person should have little to no issues with TC lockup. I hope this helps, please feel free to direct people to this thread if you see they are haveing a TC lock up issue after installing a new torque converter.
Ryan K.
LS1 Edit Beta Tester
Originally Posted by Blktie8
Under DIAGNOSTIC
MISFIRE DETECTION
There is Max temp
Min temp
To cancel misfire detection which is 141 and whaich is 142
I assume max is 142 and min is 141
Thanks
08-16-2004, 03:19 AM
#22
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Well, the problem is back. For some reason the cells in the high table change when the medium are changed. Anybody have this problem with LS1 edit. I don't understand why it is different though. The tune is the same and for some reason the tc just started unlocking. It was locking at 36mph in 4th. Now it locks up fine at first, then unlocks once the car has been driven for a while. Is there something I am missing here?
Last edited by darknight; 09-04-2004 at 08:16 PM.
10-20-2004, 05:40 PM
#25
Originally Posted by J-UNIT
I just installed a TCI super street fighter and the misfire code is popping up. Can a hypertech programmer fix this? What can?
Good luck.
Bill
10-27-2004, 12:59 PM
#26
Getting ready to install TCI street fighter TC I use Autotap....what changes do I need to make in there to prevent the lockup problem? I also am currently using HPP III on stock converter....should I back off settings (go back to stock) with new converter installed?
This converter stalls between 3000-3400
This converter stalls between 3000-3400
10-27-2004, 05:27 PM
#27
Originally Posted by ws6togo
I use Autotap....what changes do I need to make in there to prevent the lockup problem? I also am currently using HPP III on stock converter....should I back off settings (go back to stock) with new converter installed?This converter stalls between 3000-3400
Bill
11-15-2004, 08:07 PM
#28
ok what about if your cruising down the road at 55 or higher and with constant cruise throttle say 15% or coasting the car bucks and jerks. drop it into neautral and it instantly stops. stay below 55 and no problems other than surge. NO misfire codes though and factory or small stall converter 24-2600. is this the same thing as yall are talking about? thanks. hope im not highjacking.
02-13-2005, 12:50 PM
#29
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I have been a tune up and drive-ability tech for 20 years and anything rotating can cause the misfire detection to log. Belts, alternators, ac compressors, road conduction even as its addressed in the programing it still can cause things to be misinterpreted. Once in my opinion you change the rotation frequency funny things can happen. I am new on this forum and have been out of the dealership for 3 years now but still have some memory's of some real headaches. I own a 93 twin turbo Rx7 and want to join the LS1 family. I am in the process of deciding what to do. The Rx7 swap or a 240Z LS1. Any help on deciding would be greatly appreciated.
05-02-2005, 05:08 PM
#34
need help I assume that by the reference of "edit" in this post it is referring to LS1 Edit. I do not have this program. Is it recommended? I have Auto Tap EFILIVE v 7 and was thinking about getting the new bi directional adapter that makes changes to the computer permanent. Currently as soon as I unhook laptop PCM relearns its stock settings...or so I am told. Are ther other ways to change these torque converter misfire settings? I am getting ready to install TCI Super Street Fighter 3200-3500 stall.
Thanks for the help
Thanks for the help
05-02-2005, 05:28 PM
#35
No. You will need a program that allows you to alter the misfire settings. Upgrading to the new EFILIVE FlashScan would be a good choice for you seeing how you won't have to fork out a lot of money. Check out their website and see what the update cost is for you.
05-03-2005, 09:48 PM
#36
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Wow, I'm glad this thread is here.
I've been throwing the misfiring P0300 flashing MIL for awhile after my Midwest 3500 and LS6 cam installs, and wondering why in the hell my TC has quit locking up. I'm stuck with 12mpg on the highway, yay.
I've set my min/max misfire temps to 141/142, respectively, and I'll be running around Thursday and crossing my fingers. Thanks
I've been throwing the misfiring P0300 flashing MIL for awhile after my Midwest 3500 and LS6 cam installs, and wondering why in the hell my TC has quit locking up. I'm stuck with 12mpg on the highway, yay.
I've set my min/max misfire temps to 141/142, respectively, and I'll be running around Thursday and crossing my fingers. Thanks
01-22-2006, 08:15 PM
#38
TECH Senior Member
With the new TC installed, total rotating crank mass has changed significantly, so would doing a CASE relearn help...?
(Doesn't the PCM use CASE rates to determine presence of misfires...?)
Just a thought.
(Doesn't the PCM use CASE rates to determine presence of misfires...?)
Just a thought.
12-14-2007, 03:38 PM
#39
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did anybody ever figure anything else out about this? My buddy's truck wants to unlock the converter when cruising around 60mph. He has a factory sized stall but it stalls around 2400. It was dynotuned but i dont know if anything was adjusted to correct this. Any help/advice is appreciated.
12-30-2007, 12:55 PM
#40
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i know this is an old forum but after fighting this in my truck for 6 months i found that it is the minimum tcc duty cycle settings causing this. they are down in the single digits on the trucks. i dont know about the cars but this fixxed my truck.