Engine Stall/clutch in at road speed

[cfar]

I have a 06 cobalt s/c tune which i have edited to try and stop a idle problem at road speed only.If you decel and push clutch in it stalls-BTW it does not have a clutch switch due to the fact it is in a kit car(long story)
At idle no problems at all -it only happens when moving down road and you come to a stop.
Any hints or a config file to try and find it?
Thanks

[cobaltssoverbooster]

iirc your dynamic airflow limits cannot match... iirc 1500 and 1400 works ok not 1500 and 1500

here is a question for you though...what are you trying to do with this tune? I see you have your maf reading everything above 1500rpm but everything else is turned off like you are still tuning base tables.

if you want to tune the base table, fail the maf sensor out and raise the enable rpm to the max limit so it never uses it. then tell the ecu to not report its codes. on the maf fail high under diagnostics section lower it all the way to 0 to aid in complete failure of the maf sensor.
disable defco by raising the enable temps and rpms way above your max rpm range for your setup(or max them out always works just hunky dory)
disable power enrich by raising the enable rpm to max.

now tune the base table using factory ignition tables...they are safer.
when the maf is re-enabled you will be able to catch the minor term changes caused by raising ignition timing with that.

[cobaltssoverbooster]

after that's complete re-enable all the maf settings you changes and then for the maf fail high raise it to the max value so you don't throw that maf code when you decide you want to put a smaller pulley on it.

re-enable pe again. enable rpm should be around 2800-3000 i find useful anything lower is in an rpm range you shouldn't be flooring it in anyways since the load down there can cause damage.
pe throttle hot table sets the power enrich mode limit on the throttle pedal. raise the values to around 80. anything lower and your power enriching cruise which is a waste of gas.
enrichment rate set it to 2.0 and leave it alone. pe delay set to 2400 this way if for some reason the pe wants to enable below 2400 rpm this limit will delay it until it is over that value of 2400.
for EQ Ratio when you tune the base table correctly you will have to readjust these values so i would start by setting a desirable afr in a safe zone below overheating the the cylinder. to do this its simple math 14.7/desired afr = new EQ Ratio value. i would recommend setting this for a lower afr than the hotter running 11.7 range. aim for 11.3 or 11.5 just to be safe. then raise value to make richer and lower value to make leaner. do it slowly though it will jump quick with big movements.

some people lower piston protection to 3000 and some raise it all the way up to disable it. find a full factory file in the tune repository and use the value to start so you have some protection.
traction control:
general section traction control enable temp(if you want it to not use tcs mode you can raise this to around 240 and you shouldn't see tcs pulling away from your wot pulls)
supercharger section: boost limits- etc, tcs, iat, and cot boost raise to 100 to allow full torque to be applied under all wot conditions. knock limit raise to 100 whole chart, and max boost gear 1st and second you can raise to 200 for one heck of a time or with fiddling around you can raise and lower them to adjust boost in those gears to help gain traction for example on a drag launch.
boost control- desired torque and s/s raise to max table value.

now all of these values including torque section will change the loads on the engine and can skew the maf calibration in either direction so its best to set them all up in a desirable way before calibrating the maf(most people aim for traction fully disabled and boost limits maxed) its just easier to some people to remove the boost or re-enable some traction control to gain traction if you make too much power.

[cfar]

after that's complete re-enable all the maf settings you changes and then for the maf fail high raise it to the max value so you don't throw that maf code when you decide you want to put a smaller pulley on it.

re-enable pe again. enable rpm should be around 2800-3000 i find useful anything lower is in an rpm range you shouldn't be flooring it in anyways since the load down there can cause damage.
pe throttle hot table sets the power enrich mode limit on the throttle pedal. raise the values to around 80. anything lower and your power enriching cruise which is a waste of gas.
enrichment rate set it to 2.0 and leave it alone. pe delay set to 2400 this way if for some reason the pe wants to enable below 2400 rpm this limit will delay it until it is over that value of 2400.
for EQ Ratio when you tune the base table correctly you will have to readjust these values so i would start by setting a desirable afr in a safe zone below overheating the the cylinder. to do this its simple math 14.7/desired afr = new EQ Ratio value. i would recommend setting this for a lower afr than the hotter running 11.7 range. aim for 11.3 or 11.5 just to be safe. then raise value to make richer and lower value to make leaner. do it slowly though it will jump quick with big movements.

some people lower piston protection to 3000 and some raise it all the way up to disable it. find a full factory file in the tune repository and use the value to start so you have some protection.
traction control:
general section traction control enable temp(if you want it to not use tcs mode you can raise this to around 240 and you shouldn't see tcs pulling away from your wot pulls)
supercharger section: boost limits- etc, tcs, iat, and cot boost raise to 100 to allow full torque to be applied under all wot conditions. knock limit raise to 100 whole chart, and max boost gear 1st and second you can raise to 200 for one heck of a time or with fiddling around you can raise and lower them to adjust boost in those gears to help gain traction for example on a drag launch.
boost control- desired torque and s/s raise to max table value.

now all of these values including torque section will change the loads on the engine and can skew the maf calibration in either direction so its best to set them all up in a desirable way before calibrating the maf(most people aim for traction fully disabled and boost limits maxed) its just easier to some people to remove the boost or re-enable some traction control to gain traction if you make too much power.

ok made some suggested changes to the tune- Still same stall issue-I attached some drive files to view
What Am I missing?
Is it because there is no speed signal that the IAC is confused???

I removed spark smoothing in first drive file-no help
I added to underspeed spark on low rpm range in second drive file-no help
The stall in both files is where I stopped recording
Thanks

[cobaltssoverbooster]

defco vehicle enable speed to 0 if you dont have wheel speed sensors
can you load your scanner configuration file? just want to know if i need you to add some more parameters to watch during the error

[cfar]

defco vehicle enable speed to 0 if you dont have wheel speed sensors
can you load your scanner configuration file? just want to know if i need you to add some more parameters to watch during the error

used default imperial config file
can we turn dfco off all together -no cats on vehicle anyway
enable speed-0 for no abs sensors
Noticed in drive files -right before stall inj duty at 0%?? DFCO mode???
THX

[cobaltssoverbooster]

defco can be disabled by raising the enable limits to max rpm

if it is in fact defco expect it to be rich when you let off the gas.

[cfar]

dfco on or off still stalls-WTH
What else could control decell mode for the idle?
I will not do it sitting still-only when moving so it must be speed related even though there is no speed input-or is that the problem?

What sets up the IAC on decell?

[cobaltssoverbooster]

the speed sensor could very well be the problem. speed sensor should be more traction control related.

iac is actually the throttle plate itself iirc. it steppers the plate at idle then off idle tables runs the linear calibration.

i need to research my more involved files

question did you start with a clean factory file? if you did did you turn it on and drive it some to see what codes it threw? then only turn the ones that show up off? im running out of options aside from a damaged part.
and try one of the lsj files in the scanner.

iirc lsj cars log maf, map, iat, baro, stft, ltft, ignition advance and retard, narrow band bank 1 sensor 1, and fuel injectors 1-4 dc %, rpm, cam, rail pressure, etc pedal and actual if they are available.
that should snapshot the majority of what you need to see to make a conclusion.

[cfar]

I appreciate all you time and thoughts on this-Yes the file was a clean stock one and even reloaded one again.
It does not throw any codes except for a over range for MAF when customers over revs car. (over 10000 -out of range)
I am not very familiar with these but I like a challenge.
I think it may have to do with no speed signal or clutch switch signal to PCM.
But even with that the base idle should keep car from stalling-I set it at 1000 rpm and still stalls on decel-Weird
something is taking away from the idle or spark on decel.
But I could be wrong...
Thx
Frank

[cobaltssoverbooster]

i would try to wire up the clutch switch. if the clutch is depressed on a decel the ecu should auto revert the tables. you could try a speed sensor but people put these in off road buggies all the time without them so i dont think thats an issue.

i almost forgot with the ecotecs having flyby wire if the ETC systems register a fault of any kind they closed the throttle plate.
css.net:
"If the ETCS has a malfunction, the ECM shuts down the power for the throttle motor and the magnetic clutch,
and the throttle valve is fully closed by the return spring.
However, the opening angle of the throttle valve can be controlled by the accelerator pedal through the throttle cable
also, on a car ive helped on the installer ended up pinching some wires in the harness and the car would rev up but when let off the gas it would die until restarting it.

double check O2 bank 1 sensor 1 sweep and signal in scanner
and verify maf hz sweep and input signals are looking good as well. (should be a tight line of small oscillations varying in voltage with increase or decrease of airflow)
ill keep digging..im trying to find my standalone lsj factory ecu swap file. i know i have the paperwork here i just need to find it.
according to some of the partial notes i found said a swap performed here in fl died on decel due to vehicle not remaining in closed loop. to test enter vcm scanner and use vcm command controls to force into closed loop if hpt has the option available for the ecu thats currently linked.

[cfar]

wiring shows clutch switch is not connected to pcm just to starting system.
I am going to hook up vss and see what happens
THX