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. ;)

ECMlink Breaking up under boost?

Posted by Compound1g, Apr 7, 2019

Please Support STM Tuned
Please Support Southbay Fuel Injectors
  1. Compound1g

    Compound1g Proven Member

    56
    1
    Joined Feb 10, 2019
    Qualicum beach, BC, Canada
    1). No boost, vac, or exhaust leaks. No noticeable leaks
    2). Verify mechanical timing. Fresh timing belt, properly setup
    3). Verify base timing.
    4). Ignition system. 028, NGk br7es
    5). Motor health. Fresh Build, about 1k kms on it
    6). Basic throttle body adjustments. Adjusted and tight, TPS is adjusted as well
    7). Compression ratio. Je 8.5:1 pistons, but head and block decked, so probably about 9:1
    8). Wiring and sensors. All good and healthy, went over the harness and sensors when motor was out
    9). No DTC/CEL codes. No
    10). Electrical system. Decent battery, and alt seems to work well still
    11). Base fuel pressure and injector values. Rx7 550cc injectors, stock 37 psi fpr (for now anyways)
    12). Properly calibrated and configured wideband sensor. Aem 30-4110 wideband, seems to log correctly with the analog input option
    13). Type of fuel. Shell 91 octane, only option around here
    14). ECMlink how-to videos. Watched a ton, but can't find reference to this issue

    I'm having an issue trying to get wot tuning correct, I've got start, idle, and cruise damn near perfect, but at wot, between 4k and redline it starts to buck and act like a misfire a bit, not a huge amount, but it feels like a dog when it starts, and makes no power. you can see in the log that the Afr holds steady, but jumps around after 4k, it was a bit lean in this log, but I forgot to include another after I richened it up a bit, but it didn't help, did the same thing, just rich

    Ive got boost set as low as I can get it at about 16 psi, and timing is set low so as to rule that out, but I can't figure it out, I've tried leaner, richer, full rich across the board, nothing seems to really change it

    The car used to have a tuned emprom chip for this setup, but for the stock 7.9:1 Cr, so it had too much timing for the new higher Cr, hence why I got ecmlink, but it worked fantastic overall, pulled like a bat outa hell, so I know it's not something in the setup, it's a tuning issue, anyone have some thoughts on it?

    Build is on my profile

    https://www.dropbox.com/s/zs7615n0357q0ok/new log.elg?dl=0
     

    Street Build 322  1

    1993 Eagle Talon TSi AWD
    awd · manual · 1G DSM
    Loading...
  2. gdb1039

    gdb1039 Proven Member

    76
    25
    Joined Dec 16, 2007
    vancouver, Washington
    On your check list for boost leaks you put no noticable leaks, have you done a proper boost leak test? If not then that's where you should start. The tester is cheap enough to buy or make. No since in even try tuning the car until you are 100% sure there are no boost leaks.
     

    Street Build 952  9

    1995 Eagle Talon TSi AWD
    awd · manual · 2G DSM
    Loading...
  3. Compound1g

    Compound1g Proven Member

    56
    1
    Joined Feb 10, 2019
    Qualicum beach, BC, Canada
    Since it's speed density, as far as I understand, a boost leak is less important than if I had a mad, but anyways, I pressurized the system with an air compressor, and there were no leaks
     

    Street Build 322  1

    1993 Eagle Talon TSi AWD
    awd · manual · 1G DSM
    Loading...
  4. Crackerman

    Crackerman Proven Member

    103
    34
    Joined Feb 28, 2018
    Alvord, Texas
    Is a 2 step/rev limiter turned on? Invert the signal needed and see what happens
     
  5. Compound1g

    Compound1g Proven Member

    56
    1
    Joined Feb 10, 2019
    Qualicum beach, BC, Canada
    It's not that, I've got it set to 4500, and I can rev to 7k, and I have nlts off since my clutch switch is disconnected

    Honestly, it feels like a misfire or something, but I don't know why, I know it's a tuning issue, but I can't figure out if it's too lean, rich, or a timing issue, or maybe injectors or something? I know it's not the build since it worked fine with the old tune, just too much timing
     

    Street Build 322  1

    1993 Eagle Talon TSi AWD
    awd · manual · 1G DSM
    Loading...
  6. Charliethatguy

    Charliethatguy Proven Member

    31
    9
    Joined Apr 14, 2018
    Madison, Wisconsin
    I would try gaping the plugs a little tighter. Mine did that when they were to big. fine at cruise but at high rpm it would buck. I went to .027 .026 and it helped a lot.
     

    Street Build 338  3

    1992 Eagle Talon TSi AWD
    awd · manual · 1G DSM
    Loading...
    tk106 and ThunderChild like this.
  7. perrytheplatypus157

    perrytheplatypus157 Proven Member

    60
    8
    Joined Jun 18, 2017
    Fall River, Wisconsin
    The issues he's running into dont have a misfire type of breakup. If you can see the log's, they have more of a fuel cut type stutter.
     

    1K  13

    1990 Eagle Talon TSi AWD
    11.49 @ 127.56 · 1G DSM
    Loading...
  8. Charliethatguy

    Charliethatguy Proven Member

    31
    9
    Joined Apr 14, 2018
    Madison, Wisconsin
    oh ok, I didn't see a link for the logs.
     

    Street Build 338  3

    1992 Eagle Talon TSi AWD
    awd · manual · 1G DSM
    Loading...
  9. Compound1g

    Compound1g Proven Member

    56
    1
    Joined Feb 10, 2019
    Qualicum beach, BC, Canada
    Would a bad, or failing fuel pressure regulator cause this sorta issue? It would make sense right? If fuel pressure isn't raising 1:1
     

    Street Build 322  1

    1993 Eagle Talon TSi AWD
    awd · manual · 1G DSM
    Loading...
  10. perrytheplatypus157

    perrytheplatypus157 Proven Member

    60
    8
    Joined Jun 18, 2017
    Fall River, Wisconsin
    Yes. It can definitely cause the issue. Whether it's a bad regulator or boost source feeding the regulator. If you have access, take a compressor and apply pressure to the regulator, and verify that it rises 1:1. If you can add 25 psi and the gauge reads the correct pressure accordingly(probably 62 psi if base pressure is 37), then you can cross it off as not being the issue.

    You can click the dropbox he has linked. Even though it says you can't preview the information, you can still download it. From there, you can view the log.
     

    1K  13

    1990 Eagle Talon TSi AWD
    11.49 @ 127.56 · 1G DSM
    Loading...
    Charliethatguy likes this.
  11. stillrunning

    stillrunning Proven Member

    95
    42
    Joined Oct 10, 2013
    brandon, Florida
    Even if fuel pressure isn't on a 1:1 rise rate you can actually tune around it, you would be basically be increasing the injector pulse rate as fuel pressure dropped to make up for the lack of fuel pressure rise. Not that I think it's right but a non 1:1 can definitely be tuned around.
    Would probably be beneficial to actually know what your fuel pressure is when the problem occurs, maybe fuel pump pressure is dropping off.
    You should be getting a noticeable amount of knock if going lean as well, if you're going lean enough to feel it then odds are there would be allot of knock.
     

    Street Build 369  3

    1997 Mitsubishi Eclipse Spyder GST
    fwd · manual · 2G DSM
    Loading...
  12. Compound1g

    Compound1g Proven Member

    56
    1
    Joined Feb 10, 2019
    Qualicum beach, BC, Canada
    I don't have a fp gauge, and for the price of a gauge, id be able to just put a new afpr on, but anyways, what you said makes sense, if I richen it up under boost where it starts to buck (it's literally like it has no fuel for a second), it helps, but still does it a little bit, but mostly is rich overall, would also make these 550s run out pretty quick, probably around that 16 psi mark, since it seems to be ok below that

    Does that make sense? Or am I overthinking this?
     

    Street Build 322  1

    1993 Eagle Talon TSi AWD
    awd · manual · 1G DSM
    Loading...
  13. Bo0sTeD 4G63

    Bo0sTeD 4G63 Proven Member

    280
    42
    Joined Aug 31, 2008
    Miami, Florida
    When I had this problem it was either fuel cut or spark plug gap. The best way is to log fuel pressure so you can see exactly what is going on.
     

    Street Build 930  1

    1997 Mitsubishi Eclipse GSX
    awd · automatic · 2G DSM
    Loading...
    ThunderChild likes this.
  14. perrytheplatypus157

    perrytheplatypus157 Proven Member

    60
    8
    Joined Jun 18, 2017
    Fall River, Wisconsin
    https://www.amazon.com/Fuelab-71501-0-120-Pressure-Gauge/dp/B00378V6ZU
    If you have an 1/8" NPT bung on your fpr like most have, this works great and is a nice little tool. Tuning around it is definitely possible, but so is the fact that you're just plain running out of fuel. Between the 12.8 volts at WOT and the small injectors, your fuel pump may not be getting the voltage to pump out the correct pressure. And since you have less pressure at the injectors at this point, they'll flow like a smaller injector. Just food for thought, check out the 255 flow difference from 13.5 to 12 V.

    I also see a considerable amount of knock. Just so you're aware, 1* of knock is roughly 3 counts. I'm seeing upwards of 12 counts. I try to stay under 3 counts generally, unless I'm tuning a stock block where I like to see 0. Hopefully this helps!
     

    Attached Files:

    1K  13

    1990 Eagle Talon TSi AWD
    11.49 @ 127.56 · 1G DSM
    Loading...
  15. Compound1g

    Compound1g Proven Member

    56
    1
    Joined Feb 10, 2019
    Qualicum beach, BC, Canada
    I just ordered an afpr, which should be here Thursday, so I'll find out if that fixes the problem, but I think your on to something there, it's probably not enough fuel, as for the knock, ya, I'll pull more timing out

    Also, my clutch fork just snapped in half, so I'll be fixing that before I can test these theories out.
     

    Street Build 322  1

    1993 Eagle Talon TSi AWD
    awd · manual · 1G DSM
    Loading...
  16. Compound1g

    Compound1g Proven Member

    56
    1
    Joined Feb 10, 2019
    Qualicum beach, BC, Canada
    What would cause the volts to drop at wot?
     

    Street Build 322  1

    1993 Eagle Talon TSi AWD
    awd · manual · 1G DSM
    Loading...
  17. perrytheplatypus157

    perrytheplatypus157 Proven Member

    60
    8
    Joined Jun 18, 2017
    Fall River, Wisconsin
    Oh my, sorry to hear. I have a few laying around if you don't want to buy new. But you don't necessarily have to pull more timing out. Too much retard is just as bad as not enough. You can over boost more easily and create a ton more heat in the exhaust which can cause cracking. If you just make a smooth transition into upper rpm timing, it'll be a lot more efficient and better on the engine.

    As far as voltage drop goes, I would guess that your alternator is just not outputting enough voltage in the upper rpms. Start simple, check grounds and power wires throughout the chassis. This can be often overlooked. If all checks out, have the alternator tested. You should be seeing around 13.8-14.1 at WOT. FWIW, I run 2 fuel pumps, dynatek ignition system, and a nitrous solenoid, and I see 14.1 up to 8500 rpms.
     

    1K  13

    1990 Eagle Talon TSi AWD
    11.49 @ 127.56 · 1G DSM
    Loading...
  18. Compound1g

    Compound1g Proven Member

    56
    1
    Joined Feb 10, 2019
    Qualicum beach, BC, Canada
    Could be the ground system from it, I'll do some digging, as for the clutch fork, I've got another one here from a junk trans I used for parts, but it's still a royal pain in the ass to have to pull the trans again. It looks like the fork was hitting the trans, I'll have to make sure to adjust it correctly this time around
     

    Street Build 322  1

    1993 Eagle Talon TSi AWD
    awd · manual · 1G DSM
    Loading...
  19. perrytheplatypus157

    perrytheplatypus157 Proven Member

    60
    8
    Joined Jun 18, 2017
    Fall River, Wisconsin
    Sounds good. You'll get quicker after pulling the transmission a few times, but it can be a pain! Post up when you're ready to revisit this!
     

    1K  13

    1990 Eagle Talon TSi AWD
    11.49 @ 127.56 · 1G DSM
    Loading...
  20. Compound1g

    Compound1g Proven Member

    56
    1
    Joined Feb 10, 2019
    Qualicum beach, BC, Canada
    Ok, new shift fork, shifts great now
    Added an adjustable fuel pressure regulator, increases base by 10 psi, and also found the correct settings for these injectors, starts up and runs waaay better now, also added another ground strap from the alternator to the chassis, that seems to have fixed the voltage drop, holds steady at 13.3-13.7v now at all rpms.

    Don't have a log handy, but from the testing I've done so far, I should be able to get a reliable 25 psi with this setup, but I've stil got some work to do with the ve table, I'll post a log in a bit here and get some opinions on it
     

    Street Build 322  1

    1993 Eagle Talon TSi AWD
    awd · manual · 1G DSM
    Loading...
    ThunderChild likes this.
  21. Compound1g

    Compound1g Proven Member

    56
    1
    Joined Feb 10, 2019
    Qualicum beach, BC, Canada

    Street Build 322  1

    1993 Eagle Talon TSi AWD
    awd · manual · 1G 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 VR Speed Factory WheelWell.com White Shed Speed