1. Join the Community!

    DSMtuners is a massive archive of DSM information - but more importantly, it's a COMMUNITY! Join in and participate with other DSMers, and invite all of your DSM friends to make this place their home. Chat with others, create a build thread, post questions and answers. Get involved! Logging in will also remove many of the advertisements, along with this notice. ;)

ECUflash HELP fuel trims and battling richness

Posted by savethehair, Oct 12, 2019

Please Support STM Tuned
Please Support Fuel Injector Clinic
  1. savethehair

    savethehair Probationary Member

    14
    0
    Joined May 22, 2018
    Ann Arbor, Michigan
    Alright everybody, I have got my dsm still sitting in the garage after over a year and think I'm dang close to finishing it. However, there are a few more specifics that I'm getting hung up on before actually having be a somewhat reliable daily driver. Mostly just trying to figure out fuel trims. Some specifics about the vehicle;

    '97 Eagle Talon TSi AWD 4G63
    Block is completely stock (stock rods, pistons, cams, cam gears, etc.) w/ 130,000 miles on it
    New eBay big 16g w/ stock o2 housing (internal gate w/ 15lb spring)
    3.5" Straight pipe exhaust
    Aeromotive AFPR, walbro 255 w/ pump rewire
    A/C deleted, Cruise Control deleted, EGR system deleted, FIAV bypass plate
    Blackbox ECU from a '98 GST w/ ceddy mods, evoscan, and a serial to usb to log wideband values (AEM wideband)
    Stock 450cc injectors w/ stock MAF

    The car will start up easily and then go pig rich. After taking a log I see that the o2 feedback trim goes straight to +25% and it triggers the p0171 CEL. I read in Merlin's evo ecuflash tuning guide that a maxed out STFT can cause this code. After about 2min 10sec of it being maxed at +25% it immediatly goes to+ 5% and will stay there for the rest of the log. Strangely, I'm not getting any data for any other trim, the Fuel Trim Mid, Fuel Trim High, and Fuel Trim Low just give the value of 0 for all data points even after letting it idle for 20+ minutes and after driving it for 30+ minutes. The car also will drive okay, with a rich afr between 11.3-12.3, but after driving for around 10 minutes at idle it will want to bog out from being too rich. The data from o2sensor and o2sensor rear stays at 0.03904 for the entirety of the log as well.

    Attached is a log I took of the car idling for around 17minutes. Started the log right on cold startup. Displaying the non-values for the trims and the o2 feedback trimming going to 25 then 5.

    I don't know if I'm just logging wrong, (ie using the wrong MUT definitions for the trims or wrong setup in evoscan) or if I have a hardware issue (bad rear o2 or front o2) or if my flashed tune is whack (although it's pretty much 100% stock). What steps can I take to identify what my issue is?
     

    Attached Files:

    Street Build 331  8

    1997 Eagle Talon TSi AWD
    awd · manual · 2G DSM
    Loading...
  2. motomattx

    motomattx Proven Member

    1,723
    528
    Joined Dec 9, 2010
    wampum, Pennsylvania
    What injectors do you have? do you have a mass airflow sensor still? what are your coolant temp readings?
     

    Drag Race Build 2K  16

    1995 Mitsubishi Eclipse GST
    fwd · manual · 2G DSM
    Loading...
  3. stillrunning

    stillrunning Proven Member

    102
    47
    Joined Oct 10, 2013
    brandon, Florida
    In order for LTFT's to update the coolant temp needs to be at least 180 degree otherwise you'll just be using STFT's.
    With your level of mods it should be running fine.
    Make sure you have no major boost leaks otherwise you're chasing your tail
    Since you have an AFPR double check your fuel pressure with vacuum ref removed
    Might be worth swapping out the O2 sensor, it's what is used by the ecu to trim fueling
    If you want LTFT's to adjust your coolant temps need to reach 180+
     

    Street Build 419  3

    1997 Mitsubishi Eclipse Spyder GST
    fwd · manual · 2G DSM
    Loading...
  4. savethehair

    savethehair Probationary Member

    14
    0
    Joined May 22, 2018
    Ann Arbor, Michigan
    thank you for this relevant information!! I have a boost leak tester made, I will test it out tomorrow after work. As for the note about LTFT’s and coolant temp I wasn’t aware of that. I will test the tip with the AFPR verifying pressure with/without vaccum. And if nothing changes still, I’ll test out swapping the o2’s.
     

    Street Build 331  8

    1997 Eagle Talon TSi AWD
    awd · manual · 2G DSM
    Loading...
  5. savethehair

    savethehair Probationary Member

    14
    0
    Joined May 22, 2018
    Ann Arbor, Michigan
    I’m running the stock 450cc’s I own FIC 1050s but those will go in later once speed density is fully setup and everything looks good and I can get into turning it up. I’m running the maf right now it’s a 618 MAF so that I can ultimately get to building my VE tables off a solid MAF tune.
     

    Street Build 331  8

    1997 Eagle Talon TSi AWD
    awd · manual · 2G DSM
    Loading...
  6. motomattx

    motomattx Proven Member

    1,723
    528
    Joined Dec 9, 2010
    wampum, Pennsylvania
    Ok, are you running the maf tune right now or the speed density tune? you cant run the speed density with the maf btw.
     

    Drag Race Build 2K  16

    1995 Mitsubishi Eclipse GST
    fwd · manual · 2G DSM
    Loading...
  7. savethehair

    savethehair Probationary Member

    14
    0
    Joined May 22, 2018
    Ann Arbor, Michigan
    I'm running the MAF Big Maps tune right now. I know I can't run the SD tune with MAF, learned that by trial and error LOL
     

    Street Build 331  8

    1997 Eagle Talon TSi AWD
    awd · manual · 2G DSM
    Loading...
  8. delta448

    delta448 DSM Wiseman

    2,823
    90
    Joined Jan 13, 2006
    Clarksburg, West Virginia
    I'd be very surprised if this isn't your entire problem.

    The stock 609 MAF should be swapped in unless you know for absolute certain that you have accurately calibrated your rom to use the 3/S TT MAF.
     

    1K  5

    1998 Eagle Talon TSi AWD
    awd · manual · 2G DSM

    1K  11

    1997 Eagle Talon TSi AWD
    awd · manual · 2G DSM
    Loading...
  9. savethehair

    savethehair Probationary Member

    14
    0
    Joined May 22, 2018
    Ann Arbor, Michigan
    I read that the flowrates for the 609 and 618 MAF's were exactly the same though. I know that MAF parameters can be edited around in ecuflash but I haven't messed with though. What exactly needs to be calibrated on the rom to allow use of the 3/S TT MAF?
     

    Street Build 331  8

    1997 Eagle Talon TSi AWD
    awd · manual · 2G DSM
    Loading...
  10. delta448

    delta448 DSM Wiseman

    2,823
    90
    Joined Jan 13, 2006
    Clarksburg, West Virginia
    You would need to change MAF scaling, MAF smoothing table, MAF filtering, and MAF size.

    I don't know what the factory rom values were, and perhaps they are similar, but I really doubt they're the same or Mitsubishi would have just used the same part. If you want to use this MAF, your best bet is to find a 3kgt owner using ceddymods and get them to screenshot those 4 tables for you in their factory rom image. There's a rom and def file for the 99 3kgt VR4 on ceddys site, but I'm pretty sure that year used the 165 MAF.

    Remember that just because a MAF sensor can flow a certain amount or read to about the same maximum flow as another, that doesn't mean that it's linear in response or even has the same response curve as a comparable device. I would imagine a sensor from a 3.0 engine would have much more resolution in the flow rates that particular engine sees most often.
     

    1K  5

    1998 Eagle Talon TSi AWD
    awd · manual · 2G DSM

    1K  11

    1997 Eagle Talon TSi AWD
    awd · manual · 2G DSM
    Loading...
  11. savethehair

    savethehair Probationary Member

    14
    0
    Joined May 22, 2018
    Ann Arbor, Michigan
    Okay got it. Thank you for the clarification on the subject. I'll try to find someone over on the 3si forums running ceddymods with a 618 MAF or someone willing to trade a 618 for a 609.
     

    Street Build 331  8

    1997 Eagle Talon TSi AWD
    awd · manual · 2G DSM
    Loading...

Share This Page

Support Vendors who Support the DSM Community
Archer Fabrication ECM Tuning ExtremePSI Feal Suspension Fuel Injector Clinic Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications OHM Racing RockAuto SouthBay Fuel Injectors STM Tuned Track Decals Track Sculptures VR Speed Factory WheelWell.com