need help with a/f at idel
need help with a/f at idel
ok ive had some pretty bad luck with last 2 tuners ive dealt with. (both big names)
i just installed a wideband at idel my a/f is off the aem wideband sometimes its 17-18 or --. under boost its fine its just at idle and at cruise.
curising its at 15-16 it use to be worse but the 2nd tuner did a maf scale i guess.
so is there an easy way to fix my idle a/f? i went from 500ft elevation to 3300ft elevation.
i have my own tatrix cable and pretty familar with ecu flash just dont know what i need to change to fix this. i dont really want to pay another tuner to fix this if i can get help here to fix it.
edit i attached mitsu log
here is my log
Attachment 116358
i just installed a wideband at idel my a/f is off the aem wideband sometimes its 17-18 or --. under boost its fine its just at idle and at cruise.
curising its at 15-16 it use to be worse but the 2nd tuner did a maf scale i guess.
so is there an easy way to fix my idle a/f? i went from 500ft elevation to 3300ft elevation.
i have my own tatrix cable and pretty familar with ecu flash just dont know what i need to change to fix this. i dont really want to pay another tuner to fix this if i can get help here to fix it.
edit i attached mitsu log
here is my log
Attachment 116358
Last edited by filter; Feb 14, 2008 at 03:56 PM.
Well, I think we need to know if the AF is showing lean on the wideband because of an exhaust leak somwhere before the wideband or because the fuel trims are maxed out positive.
Do a log with Mitsulogger (or the correct EvoScan formulas) for the LTFT Lo and LTFT Mid during idle and cruise. Log your STFT as well. Make sure the car is warmed up first.
If you fuel trims aren't maxed out, then any tuning isn't going to help, because the ECU is already able to maintain a stoich burn. In that case, it's most likely the wideband that is giving a false reading due to an exhaust leak or a bad sensor.
Now, if the fuel trims are maxed out positive, then we can tune that out, with MAF scaling, injector tuning, etc. Let us know what you find.
Eric
Do a log with Mitsulogger (or the correct EvoScan formulas) for the LTFT Lo and LTFT Mid during idle and cruise. Log your STFT as well. Make sure the car is warmed up first.
If you fuel trims aren't maxed out, then any tuning isn't going to help, because the ECU is already able to maintain a stoich burn. In that case, it's most likely the wideband that is giving a false reading due to an exhaust leak or a bad sensor.
Now, if the fuel trims are maxed out positive, then we can tune that out, with MAF scaling, injector tuning, etc. Let us know what you find.
Eric
Well, I think we need to know if the AF is showing lean on the wideband because of an exhaust leak somwhere before the wideband or because the fuel trims are maxed out positive.
Do a log with Mitsulogger (or the correct EvoScan formulas) for the LTFT Lo and LTFT Mid during idle and cruise. Log your STFT as well. Make sure the car is warmed up first.
If you fuel trims aren't maxed out, then any tuning isn't going to help, because the ECU is already able to maintain a stoich burn. In that case, it's most likely the wideband that is giving a false reading due to an exhaust leak or a bad sensor.
Now, if the fuel trims are maxed out positive, then we can tune that out, with MAF scaling, injector tuning, etc. Let us know what you find.
Eric
Do a log with Mitsulogger (or the correct EvoScan formulas) for the LTFT Lo and LTFT Mid during idle and cruise. Log your STFT as well. Make sure the car is warmed up first.
If you fuel trims aren't maxed out, then any tuning isn't going to help, because the ECU is already able to maintain a stoich burn. In that case, it's most likely the wideband that is giving a false reading due to an exhaust leak or a bad sensor.
Now, if the fuel trims are maxed out positive, then we can tune that out, with MAF scaling, injector tuning, etc. Let us know what you find.
Eric
hmm went tad over my head.
the 2nd tuner fixed the curising part some but not the idel i do hit 11 under full boost wot. i turly beleive its maf scaling but ill check for leaks.
ill also do a log and post it.
What I have described above is to test whether or not there is a leak before your wideband, causing the lean readings. Your idle is lean for one of two reasons:
1. Your LTFT Lo is maxed out and the ECU can't provide enough fuel to maintain 14.7:1
2. Your LTFT Lo is fine and you are running 14.7:1, but there is a leak before your wideband, so your wideband is showing a leaner reading.
Do you have MitsuLogger or Evoscan? If you do, then do a log at idle (after your car is warmed up) and tell us what your LTFT Lo and STFT are from the log.
If those values are OK, then you may have a leak before your wideband.
If those values aren't OK (+12.5 LTFT for example), then you can use the first cell in your MAF scaling table to fix your idle.
Eric
1. Your LTFT Lo is maxed out and the ECU can't provide enough fuel to maintain 14.7:1
2. Your LTFT Lo is fine and you are running 14.7:1, but there is a leak before your wideband, so your wideband is showing a leaner reading.
Do you have MitsuLogger or Evoscan? If you do, then do a log at idle (after your car is warmed up) and tell us what your LTFT Lo and STFT are from the log.
If those values are OK, then you may have a leak before your wideband.
If those values aren't OK (+12.5 LTFT for example), then you can use the first cell in your MAF scaling table to fix your idle.
Eric
What I have described above is to test whether or not there is a leak before your wideband, causing the lean readings. Your idle is lean for one of two reasons:
1. Your LTFT Lo is maxed out and the ECU can't provide enough fuel to maintain 14.7:1
2. Your LTFT Lo is fine and you are running 14.7:1, but there is a leak before your wideband, so your wideband is showing a leaner reading.
Do you have MitsuLogger or Evoscan? If you do, then do a log at idle (after your car is warmed up) and tell us what your LTFT Lo and STFT are from the log.
If those values are OK, then you may have a leak before your wideband.
If those values aren't OK (+12.5 LTFT for example), then you can use the first cell in your MAF scaling table to fix your idle.
Eric
1. Your LTFT Lo is maxed out and the ECU can't provide enough fuel to maintain 14.7:1
2. Your LTFT Lo is fine and you are running 14.7:1, but there is a leak before your wideband, so your wideband is showing a leaner reading.
Do you have MitsuLogger or Evoscan? If you do, then do a log at idle (after your car is warmed up) and tell us what your LTFT Lo and STFT are from the log.
If those values are OK, then you may have a leak before your wideband.
If those values aren't OK (+12.5 LTFT for example), then you can use the first cell in your MAF scaling table to fix your idle.
Eric
i have both ill do this after work today. ill post up if you dont mind checking back and giving your thoughts on it.
Also post a screenshot of your MAF scaling table.
Eric
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no i dont have a barometer log
but mods are as follow
2006 evo ix
BR tbe
BR intake cone (pipe is on order)
cosworth cams, arp head studs
BR UICP
Ams FMIC and LICP
forge MBC
AMS fuel rail
walboro fuel pump.
here is my car idling i dont have my wide band hooked up to log in a computer but it hits 17.8 then off the scale.
i put my maf scale pic in first post
i put my maf scale pic in first post
Last edited by filter; Feb 14, 2008 at 03:55 PM.
OK, I'm pretty sure I can tell you how to fix this with the MAF scaling table, but first I need to see a few minutes of an idle log. Don't worry about putting more miles on it. I can tell from the STFT and the LTFT.
Btw, your Maf scaling table is stock. If you right-click on the maf sclaing table in ECUFLash and click Edit Map, is your scaling for the X axis uint8? If so, then your MAF scaling table hasn't been changed.
Eric
Btw, your Maf scaling table is stock. If you right-click on the maf sclaing table in ECUFLash and click Edit Map, is your scaling for the X axis uint8? If so, then your MAF scaling table hasn't been changed.
Eric