Automatic car stalling while coming to a stop/slowing down

[Soloside]

After reading some threads here about people's AT cars stalling, I finally realized that I wasn't the only one with the issue.








I've included a log that I did with the Ecutek BT dongle and hopefully a few guys can chime in. The stall happens towards the end.










http://www.datazap.me/u/soloside/log...?log=0&data=11


http://www.datazap.me/u/soloside/log...?log=0&data=11

[JermMX5]

Originally Posted by Soloside

After reading some threads here about people's AT cars stalling, I finally realized that I wasn't the only one with the issue.

Upload your log to datazap.me and it will be alot easier for people to view it.

[Soloside]

Originally Posted by JermMX5

Upload your log to datazap.me and it will be alot easier for people to view it.

Thank you very much!

[Wayno]

Your tuner will tell you whether it's a software problem, or the other option which is that your transmission is not unlocking from beating the shit out of it without an atf cooler or changing fluid.

[alan.chalkley]

I have had this problem twice after routine service on my MT car.
My guesstimate is that too much throttle body cleaner was used.
It cleared itself after a few hours of driving.

[steve99]

You long term fuel trims look suspect LTFT up to almost 20% in places.

you might have an exhaust or intake leak throwing the fueling off

[Soloside]

Originally Posted by Wayno

Your tuner will tell you whether it's a software problem, or the other option which is that your transmission is not unlocking from beating the shit out of it without an atf cooler or changing fluid.

Tuner's done quite a few automatics and none of them have had the issue as often as mine. I've gone out of the way and even purchased another automatic transmission to see if it was indeed just caused by me beating on my original trans, but all I do are just highway miles. I'm currently running motul fluids AND have the stark ATF cooler and it still occurs.

[steve99]

OK


Im assuming your boosted and have a flex kit


Few things that are weird


LTFT are way high (20%) in first log but ok in second 5% or less ir normal
Maybe you have a problem with flex sensor or wiring ??
or leaky bov or exhaust leak


Also noticed the Battery volts die off from 14v to 12v as the car almost stalls. Its possible your battery is very weak




see here
http://www.datazap.me/u/soloside/log...zoom=4476-5329


also check your Direct Injection computer under bonnet is securely bolted to brackets with all bolts it gets its earth via the mount bolts


you can likely fix the stall by increasing the values in the "overrun fuel resume" tables but its likely due to hardware issue

[Blood]

Originally Posted by Soloside

Tuner's done quite a few automatics and none of them have had the issue as often as mine. I've gone out of the way and even purchased another automatic transmission to see if it was indeed just caused by me beating on my original trans, but all I do are just highway miles. I'm currently running motul fluids AND have the stark ATF cooler and it still occurs.

If you have no hardware issues (exhaust or vacuum leaks, bad injectors) then my guess is your injector scaling was not done properly (or at all).

Who is your tuner? I'm guessing Moto-East by your location and title? I had this issue on my AT car running a Moto-East tune after installing larger (700cc) injectors. The car would stall when coming to a stop in 2nd gear around 50% of the time (I always drove in manual mode), didn't matter if the engine was cold or warmed up. The "fix" that was put in place was to raise the target idle across the board to a minimum of ~750 rpm. It stopped the stalling for the most part, but there was still a fairly severe stuttering from the engine (enough to feel the car shaking) when coming to a stop.

It never got completely fixed and I eventually changed tuners (to James Martin @ HRI Tuning), and didn't have the issue on the new tune.

[Wayno]

Originally Posted by steve99

OK
Also noticed the Battery volts die off from 14v to 12v as the car almost stalls. Its possible your battery is very weak

Mine drops to as low as 12.2V, normal.

[Wayno]

Originally Posted by Blood

If you have no hardware issues (exhaust or vacuum leaks, bad injectors) then my guess is your injector scaling was not done properly (or at all).

Who is your tuner? I'm guessing Moto-East by your location and title? I had this issue on my AT car running a Moto-East tune after installing larger (700cc) injectors. The car would stall when coming to a stop in 2nd gear around 50% of the time (I always drove in manual mode), didn't matter if the engine was cold or warmed up. The "fix" that was put in place was to raise the target idle across the board to a minimum of ~750 rpm. It stopped the stalling for the most part, but there was still a fairly severe stuttering from the engine (enough to feel the car shaking) when coming to a stop.

It never got completely fixed and I eventually changed tuners (to James Martin @ HRI Tuning), and didn't have the issue on the new tune.

^^ This is your answer here.

Not so much the scaling, more so the fact that they are relying on PI instead of using the DI at low speed like they should.

Using super-sized/slow ports only and not the much more accurate/fast DI's while the TQ is dragging the engine down is a good way to stall the motor.

This is your car.
The marks are 3rd, 2nd, 1st.

http://www.datazap.me/u/soloside/log...4928-4868-4800

This is what it should look like.
The marks are 3rd, 2nd, 1st.

http://datazap.me/u/wayne/stg2-ace-f...1102-1132-1156

Notice the AFR at the absolute lowest rpm is < 14.7, where as yours is still infinite (NO FUEL). Engine can't run without fuel. That 0.4s ms doesn't even make a dent in AFR.

You could say that you could adjust the spray from the ports or that there's some hardware issue with the ports or a hundred other BS excuses, but the fact that PI is being used at all at such low rpm on 6AT regardless of stock injectors or not, is a tune issue.

Which is what the tuner should pick up when you show them the log above, which is what you pay them for.

[BirdTRD]

I had very similar issues immediately after I upgraded the injectors to id1050x's... stalls coming off high idle, idle hunting after high idle and stalling/near stalling at tip in. I tried with 93 and Ethanol (got it to E65) but it made no difference. Checked for leaks...none, ground to injector ECU was <1 ohm, reseated the injector ECU connectors, no change.

I sent @moto-mike a few logs, he made some changes and sent me a revision right away. So far, so good. I'm back on 93 octane now and no stalls, idle weirdness or hunting. As soon as I can burn off this tank of 93, I'll check it with E85 (if it's not too cold out by then) but I suspect I'll be fine with ethanol as well.

[Soloside]

Wanted to give everyone an update.



https://datazap.me/u/soloside/log-1508120355?log=0&data=


My Omni sensor went kaput and was able to put a new one in. Was also able to get some proper scaling with the DI/PI. Hopefully the logs show the same thing as what I'm experiencing, which is no-stalling.

[BirdTRD]

Originally Posted by Soloside

Wanted to give everyone an update.

https://datazap.me/u/soloside/log-1508120355?log=0&data=

Not sure why but the log won't open in Datazap, just says "generating chart". Did you remove all the lines above the column names before uploading? i.e.:

#Encoding: UTF-8
#App name: ProECU
#App version: 1.0.0.28777
#Ecu: US BRZ Auto (ZA1JB01D)
#CALID: ZA1JB01D
#RaceROM version: 14615