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Thread: 2 first gen tts swapd 3 Ecus 4 mafs an stil chasing bs

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    2 first gen tts swapd 3 Ecus 4 mafs an stil chasing bs

    alrite ones my drag car and the other is a stock 92 stealth rt turbo. I made a video too hopefully narrow down questions and possibilities. I think I may be hitting thatwall that happens when you think about a problem too long and end up confusing yourself and missing an answer thats right in front of you.

    heres tha video:

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    I didn't watch the entire video, but this is what I observed on your SAFCII.

    Airflow displays 3 Hz almost continuously and then it briefly jumped into the teens before going back to 3 Hz. Normally you should see something above 30 Hz for idle. If the ECU sees too small of an airflow signal, it will cap it (let's say 25Hz as an example).

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    I didn't watch the entire video, but I'll add some things to think about.

    #1: Your car will never run without a MAF and using an interceptor for tuning and larger injectors, the ECU will flood the car out. When you unplug the MAF, it's the same thing as unplugging the AFC and trying to run the car on big injectors, not gonna happen.

    #2: Since one MAF gives the AFC a reading, by elimination every other MAF that doesn't output a reading is broken, because you just tested continuity in the wiring. IIRC idle Hz should be around 25-50Hz according to the service manual.

    #3: Might as well throw away any MAF that has the center screen gutted out, they never work right and you'll end up with weird issues and weird settings to try and tune it, not worth the trouble and doesn't add any flow anyways.

    #4: the type of injectors matters, if you have EVO 560's for example, you're gonna have a hell of a time tuning them with an AFC because their latencies are way off the stock injectors.

    #5: Any leaks in the entire intake tract and all bets are off. That idle Hz reading will spill the beans on your leaks.

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    Quote Originally Posted by BlackStealth View Post
    I didn't watch the entire video, but this is what I observed on your SAFCII.

    Airflow displays 3 Hz almost continuously and then it briefly jumped into the teens before going back to 3 Hz. Normally you should see something above 30 Hz for idle. If the ECU sees too small of an airflow signal, it will cap it (let's say 25Hz as an example).
    thanks for tha reply. i wasnt sure what idle value should be. the car did crank long enough too allow tha safc to start up and show me a value before dying and it showed around 62 on one instance and upper 40s on another try.

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    Quote Originally Posted by anyonebutme View Post
    I didn't watch the entire video, but I'll add some things to think about.

    #1: Your car will never run without a MAF and using an interceptor for tuning and larger injectors, the ECU will flood the car out. When you unplug the MAF, it's the same thing as unplugging the AFC and trying to run the car on big injectors, not gonna happen.
    i get that i didnt purposely run it witout tha maf. it was an accident. and since these always shutdown quickly if tha maf is unplugged, i knew there was something to look at. however, 4 bad mafs??????

    Quote Originally Posted by anyonebutme View Post
    #2: Since one MAF gives the AFC a reading, by elimination every other MAF that doesn't output a reading is broken, because you just tested continuity in the wiring. IIRC idle Hz should be around 25-50Hz according to the service manual.
    thats what doesnt make sense. the one completely gutted one came off my first vr4 and it ran fine, i daily drove it. and the reading the one does give, is the same value as key on engine off. the other 3 at least give the varying airflow signal they should, until the car dies.

    Quote Originally Posted by anyonebutme View Post
    #3: Might as well throw away any MAF that has the center screen gutted out, they never work right and you'll end up with weird issues and weird settings to try and tune it, not worth the trouble and doesn't add any flow anyways.
    i would agree that they are not preferrable, however they are useable and driveable with gutted honecombs, but i was only using them as testers anyhow.

    Quote Originally Posted by anyonebutme View Post
    #4: the type of injectors matters, if you have EVO 560's for example, you're gonna have a hell of a time tuning them with an AFC because their latencies are way off the stock injectors.
    they are rc 550s, ill have to look back, i thought i mentioned it in video, it was difficult to try to remember every variable as i was shooting the video and thinking about troubleshooting.

    Quote Originally Posted by anyonebutme View Post
    #5: Any leaks in the entire intake tract and all bets are off. That idle Hz reading will spill the beans on your leaks.
    i pressure tested the intake tract on both cars and corrected leaks if present.

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    i had hoped that the video would simplify putting the information out there instead of a long dictation. maybe i was wrong. i tried trimming it to only pertinent info to cut down run time.

    heres as much as i can remember right now for inputs:

    3000:
    rc 550cc injectors (cleaned and flow tested)
    safc 2
    RAN SUCCESSFULLY ON THESE 2 WITH AROUND -42% CORRECTION ACCORDING TO JEFF LUCIUS' SITE
    92 vr4 ecu
    another 92 vr4 ecu
    mafs #165, #165, #055, #609

    stealth:
    oem 360cc injectors
    92 stealth tt ecu
    tested with the 2nd 92 vr4 ecu as well, no change
    also same mafs used above

    cars running with exact same problems on all mafs

    no ckp sensors have been changed or swapped

    no coilpacks, plugs, wires, or ptus have been changed or swapped on stealth, the 3000 mite have over a year ago when i was troubleshooting what turned out to be a bad safc 1.

    however none of those have been changed for this set of tests.

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    FYI, Apexi SAFC I and Apexi SAFC II never worked right on my 93 car, they worked 99% well, and once in a while it would glitch. The same SAFC worked fine on my Talon, however the Stealth rejected it. When I switched to Emanage, it worked just fine. I'm not saying this is your problem, but I just wanted to point that out.

    When your ECU sees an airflow Hz signal very low, it is going to automatically bump that 3 Hz to 25 Hz (approx) in order to keep that idle from stalling. Now because you're relying on the ECU to keep idle, it's masking the original problem (Airflow Hz number). Increasing the throttle should increase the airflow (Hz), but it is not, and this is the issue.

    You need to investigate why the Airflow Hz number is so low -- faulty wiring? faulty SAFC?

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    one thing ive been debating is electrical backfeeding. I dont consider myself what you would call a natural when it comes to understanding electric.
    I remember years ago hearing something(possibly folklore) that a bad iac could backfeed and damage tha ecu.
    can the maf do this to an ecu??????
    Last edited by Vrfury; 07-24-2018 at 03:02 PM.

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    Quote Originally Posted by BlackStealth View Post
    FYI, Apexi SAFC I and Apexi SAFC II never worked right on my 93 car, they worked 99% well, and once in a while it would glitch. The same SAFC worked fine on my Talon, however the Stealth rejected it. When I switched to Emanage, it worked just fine. I'm not saying this is your problem, but I just wanted to point that out.

    When your ECU sees an airflow Hz signal very low, it is going to automatically bump that 3 Hz to 25 Hz (approx) in order to keep that idle from stalling. Now because you're relying on the ECU to keep idle, it's masking the original problem (Airflow Hz number). Increasing the throttle should increase the airflow (Hz), but it is not, and this is the issue.

    You need to investigate why the Airflow Hz number is so low -- faulty wiring? faulty SAFC?
    thanks for tha input blackstealth and everybody for that matter. this shit wouldnt let me sleep las nite and I wrk 14hrs today.
    edit:another thing tho is that the stealth is doing the exact same thing without an safc or upgraded injectors. I realy hav begun too think mitsubishi flips a switch from a satellite evrytime I buy one of their cars jus so it has fukd up problems I cnt fix......
    Last edited by Vrfury; 07-24-2018 at 03:07 PM.

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    update: my friend picked up on the wiring harness an this happened.
    ......

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