Hello Guys,

been looking at one 2010 evo x recently.

After change of exaust system, we uprated boost/timing/fuel tables/airflow checks and etc.

And sometimes in during wot pulls ir 3rd and allways in 4th we are getting strange cut. We have tried various limits (airflow too) removal - no sucsess. Changed MAF - no difference.

What is interesting, that there is no visible affect on readings during knock (exept throtle closing and exesive knock ocurense, which doesnt happends if there is no cut). No WB/timing/other changes during cut.

Recently i have found that MAT allways shows -40 degrees Centigrade. Is this could be the problem at WOT? Is reading from MAT is used for calculations in ECU? Or it is using only IAT?

Also in the last day there is very unnormal idle, and sometimes stalling of engine occuring.

attaching 2 logs with cut @5500rpm and @6-7krpm. also log of idle

Any ideas?

 

Describe the "cut" more. That isn't a very descriptive word.

Did you check your boost limit / boost cut tables?

 

Sounds like you need to turn the Limiters off

 

it just cuts i am keeping pedal at wot and it just drops 1000rpm and it feels like you hit the wall

what you meen to turn limiters of?
I have checked all the DTC's in misc list and increased airflow and torque limiters. if there is any other way, please inform me.

i am boosting under boost cut limiters, what i had set.

 

Ok if it cuts like you are hitting a wall and trying to throw you out the front window then you are hitting fuel cut.

It is load based and labeled "Boost Limit" in EcuFlash.

If Boost drops all of a sudden and your idle is around 2,000 rpm then you are triggering the Airflow/Torque limiters.

If it is slight tugs then it's ignition breakup.

 

few moments ago increased boost cut to its maximum position at 319%. We are not overboosting so it is quite safe. but still experiencing cut.

Increased airflow/torque maps alot - still it cuts. just it is interesting, that it comes now at various load places. and it is not costant.

Is there any way to disable theese limiters at all? just for testing reasons, because now it seams that it is not ecu issue.

boosting 24.5-25 in 3rd and 25.5-26 in 4th.

 

Oh so you haven't turned the Airflow/torque limiters off then like I said in post #8?

Yes, do that. That is your issue it sounds like. It should also throw a CEL and drop boost (if you are still using ECU Boost), and also idle at 2k.

See this thread: https://www.evolutionm.net/forums/ev...p1238-etc.html

 

i will read this thread in few moments, but i belive i have did it. see picture.

 

Are you getting a CEL triggered when the cut happens?

If you have for sure disabled the airflow/torque limiters (making sure the before values are correct before changing to FFFF)

Sure you aren't getting dramatic boost error correction, and sure you aren't getting fuel cut.

Then I would think it is misfires, espically since you said it happens at random RPM.

Is your wideband AFR in your logs correct? If so you are running the car super rich, which can cause misfires.

 

thanks, for info. it is nice sometimes to confirm what you have read

tomorow i will try to change plugs to proper iridiums and will check fueling for sure. but during cut WB shows - ok.

Values have been ok before changing them to 0xFFFF.

Thanks for info.

p.s. i dont get any CEL's arter update of rom with Tephra DTC code "disablers", but cut is still there.

 

I bet if you leaned out the mixture from 10.1 to even 10.9-11.1 you would no longer get the misfires.

 

I was gonna say the initial description sounded a lot like random missfire... lean that bish out son.. carefully of course, maybe pull a few degrees of timing till you get the AFR under control then start adding back the timing a bit.

 

i did today, and it is better. fuel is now @ 11's but theese plugs are gone. ordered 9's tomorow will be resumed.

What is interesting after swap of plugs (had one more set of stocks around) idle became normal - so it is plugs i believe, they are not handling so much boost at this afr.

will update tomorow.

 

sory for long wait if someone waited

been on hollidays. just after change of plugs everything came back to normal. car pulls now like train

thanks for suggestions