hot starts, lean at idle
#1
hot starts, lean at idle
ORginally I heard this problem was caused by ideal gas law causing the ecu to run lean from iat heat soak. Now though I think there maybe something else causing this issue. I used brains anti ideal gas law correction table to keep GAIR at 100. that works great but the problems is still durning hot restarts, say let the car sit for 10-30 minutes or so and come back and restart. She'll end idling very lean.
But if you start going after a certain rpm it seems to stop leaning out and goes back to running off the ve fuel map fine. Its not timed based as much or if it is after a certain rpm value it stops but will keep going till certain ammount of running.
Any ideas at what I should look at. I just hope this isn't something hardcoded.
thanks
But if you start going after a certain rpm it seems to stop leaning out and goes back to running off the ve fuel map fine. Its not timed based as much or if it is after a certain rpm value it stops but will keep going till certain ammount of running.
Any ideas at what I should look at. I just hope this isn't something hardcoded.
thanks
#3
well my logs are long and not enough space here to upload, but yes gair is at 100 durning hot starts.
the IAT though is here, hard to tell but where the brass fittings are. There is a T coming off the itnercooler piping. So its not in the direct airflow to the engine unfourntaly. I've been meaning to move it more in the flow, just haven't gotten around to it.
Uploaded with ImageShack.us
the IAT though is here, hard to tell but where the brass fittings are. There is a T coming off the itnercooler piping. So its not in the direct airflow to the engine unfourntaly. I've been meaning to move it more in the flow, just haven't gotten around to it.
Uploaded with ImageShack.us
#9
Any progress on this?
I've noticed something similar with my DIYPNP. I have attached a log that I took on startup (log begins shortly after the engine starts)
There is a drop in RPM and the AFR gets a bit richer. I'm not sure what is causing the drop in RPM though as the idle valve PWM isn't changing and I can't find anything else in the log that explains the drop in RPM.
I've noticed something similar with my DIYPNP. I have attached a log that I took on startup (log begins shortly after the engine starts)
There is a drop in RPM and the AFR gets a bit richer. I'm not sure what is causing the drop in RPM though as the idle valve PWM isn't changing and I can't find anything else in the log that explains the drop in RPM.
#13
restructing my dead thread
Here is a data log of a hot lean start
http://www.mediafire.com/?23rzszb4gwanxa2
you can notice that its around 18+ afrs after reving it around a tad it will come down to 17~s and finally driving it around a tad it will be come down to where it should be low 15s high 14s
the sensor was relocated to in airflow and it reads 103-104f at hot start and while running between 102 and 104.
You will notice though I'm actually have higher PW at lean hot start idle than I do at normal idle
Yeah I think there is some other variable in the system that needs to be figured out.
Here is a data log of a hot lean start
http://www.mediafire.com/?23rzszb4gwanxa2
you can notice that its around 18+ afrs after reving it around a tad it will come down to 17~s and finally driving it around a tad it will be come down to where it should be low 15s high 14s
the sensor was relocated to in airflow and it reads 103-104f at hot start and while running between 102 and 104.
You will notice though I'm actually have higher PW at lean hot start idle than I do at normal idle
Yeah I think there is some other variable in the system that needs to be figured out.