swingtan
December 16th, 2008, 08:59 AM
Some time back I posted a thread on some timing issues that I believed were related to the TCS MAFless patches.
http://forum.efilive.com/showthread.php?t=7401
The solution in this case was to remove spark smoothing, which was causing some weired timing problems.
Over the past few weeks I've been battling with a rather strange issue that again seems to be TCS Patch related. It's still a stutter issue with leads me to think that spark smoothing was not the real cause of the original problem, but possibly how the patch was working. Here's the point form of what I've seen.
Vehicle is a VZ L76 M6 with 4>1 longs and a 2.5" twin system. the rest is stock apart from the tune.
When cresting a hill in a high gear ( 5th or 6th ) and I come off the throttle a bit so as not to start building speed, The car feels like it hits a wall for a split second and then continues on. Sometimes there is a very small amount of bucking involved, but normally it's a single hit. This is quite easy to reproduce by simply pressing on the throttle and releasing it, not quite all the way. See log Stutter_01.efi and Stutter_02.efi
When applying very light throttle, the car car start some serious bucking, to the point where you can hear the slack in the drive train being taken up as it goes from drive to overdrive and back again. this can also be invoked by turning of DFCO and applying a very small amount of throttle when coating down a hill. See log Stutter_03.efi
The similarities with the original thread are numerous,
Only occurs at light throttle.
Commanded spark is oscillating up to 12'.
Removing the TCS patches also removes the symptoms.
Changing the settings for spark smoothing has no effect at all.
I've tried a large number of things in an attempt to stop this.
Varied the high / low spark tables in the effected cells between 16' and 45'
Varied the idle spark table between 16' and 45'
Varied the coast down spark table between 16' and 45'
Varied the DFCO spark timings and entry timings
Varied the torque management settings
Varied the TCS settings including turning TCS off at the switch
All this had minimal if any effect on the problem. The only thing that has made a difference is to remove the TCS patches completely, which has completely removed the problem. So I still believe that there are issues with the TCS patches, at least for my OS - 12607218.
Comments anyone?
Simon.
EDIT: Sorry, I just realised I should have posted this in the E38 section. Mods, please move it if required.
http://forum.efilive.com/showthread.php?t=7401
The solution in this case was to remove spark smoothing, which was causing some weired timing problems.
Over the past few weeks I've been battling with a rather strange issue that again seems to be TCS Patch related. It's still a stutter issue with leads me to think that spark smoothing was not the real cause of the original problem, but possibly how the patch was working. Here's the point form of what I've seen.
Vehicle is a VZ L76 M6 with 4>1 longs and a 2.5" twin system. the rest is stock apart from the tune.
When cresting a hill in a high gear ( 5th or 6th ) and I come off the throttle a bit so as not to start building speed, The car feels like it hits a wall for a split second and then continues on. Sometimes there is a very small amount of bucking involved, but normally it's a single hit. This is quite easy to reproduce by simply pressing on the throttle and releasing it, not quite all the way. See log Stutter_01.efi and Stutter_02.efi
When applying very light throttle, the car car start some serious bucking, to the point where you can hear the slack in the drive train being taken up as it goes from drive to overdrive and back again. this can also be invoked by turning of DFCO and applying a very small amount of throttle when coating down a hill. See log Stutter_03.efi
The similarities with the original thread are numerous,
Only occurs at light throttle.
Commanded spark is oscillating up to 12'.
Removing the TCS patches also removes the symptoms.
Changing the settings for spark smoothing has no effect at all.
I've tried a large number of things in an attempt to stop this.
Varied the high / low spark tables in the effected cells between 16' and 45'
Varied the idle spark table between 16' and 45'
Varied the coast down spark table between 16' and 45'
Varied the DFCO spark timings and entry timings
Varied the torque management settings
Varied the TCS settings including turning TCS off at the switch
All this had minimal if any effect on the problem. The only thing that has made a difference is to remove the TCS patches completely, which has completely removed the problem. So I still believe that there are issues with the TCS patches, at least for my OS - 12607218.
Comments anyone?
Simon.
EDIT: Sorry, I just realised I should have posted this in the E38 section. Mods, please move it if required.