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ECMlink Reading wrong RPM?

Posted by polverari, Jul 13, 2020

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  1. polverari

    polverari Proven Member

    Joined Jan 29, 2018
    São Paulo, South America
    (As I usually speak in all my posts, I apologize if I miss a few words, English is not my native language)

    I have a 2g and I rarely accelerate above 6500 rpm. However, two days ago I decided to record a LOG speeding up to 7000 rpm, just to see the results. Below is a print screen of the video I made while accelerating.


    Here, the video:

    As you all can see, the RPM gauge is on 7000rpm and the speed at 169 km/h
    However, my car ALWAYS show 12km/h more, so, i was at 157 km/h

    Considering that I was in third gear, you can check out that a 2g GST eclipse at 7000 rpm is about 155 km / h (I went on several youtube videos to check this out, like these:)


    As you can see...
    6000 rpm = 84 Miles per hour
    1000 rpm = 84/6 = 14
    7000 rpm = 14x7 = 98 miles per hour = 156.8 km/h

    Ok, now, the log:


    (I will send the complete log here as a attached file)

    Observing the exact moment of the 7000 rpm of the video, in the log, we conclude:
    - 6178 rpm
    - 142 km/h

    Thats really weird...

    Today I used the free time to clean the contacts of my powertransistor and install new coils, however, i did not make more tests (yet). I will record more logs tomorrow.

    What is puzzling me is:

    If the RPM
    the panel is wrong, the panel speed is also wrong.

    If the ECMlink is really 100% correct, my panel is absurdly wrong.

    If my panel is wrong, it is only wrong at high RPM, as it marks correctly (with little margin of error) before 6000 rpm.

    If the ECMlink is wrong, I have no idea why this is happening.

    Do you have any tips, suggestions or opinions about it all?

    Thank you! :)

    Attached Files:

  2. rabenne

    rabenne Proven Member

    Joined Apr 21, 2006
    Racine, Wisconsin
    I am not sure, but I dont think your gauge faces are factory. That means the needles have been removed and put back on. I am betting the panel is wrong for RPM and Speed. ECMlink is probably correct.

    Another term that is slightly more common for the panel is "cluster". Not picking on you, just an FYI. If you are searching around it might be a more helpful keyword for you

    Street Build 8K  23

    1995 Eagle Talon TSi
    awd · manual · 2G DSM

    332  7

    2008 Lancer Evolution MR
    awd · automatic · Lancer Evolution

    Street Build 542  5

    1996 Mitsubishi Eclipse GSX
    awd · automatic · 2G DSM
    polverari likes this.
  3. motomattx

    motomattx Proven Member

    Joined Dec 9, 2010
    wampum, Pennsylvania
    ^^^ This is my first thought, the needle could also be sticking on a high spot on the gauge face.

    Drag Race Build 4K  24

    1995 Mitsubishi Eclipse GST
    fwd · manual · 2G DSM
    polverari and rabenne like this.
  4. polverari

    polverari Proven Member

    Joined Jan 29, 2018
    São Paulo, South America
    Thanks for the advice about "cluster"!

    Btw... If both gauges are wrong, how i got 155 km/h gps speed (using an app on smartphone) in third gear? That is what is messing me...

    BUT, tomorrow i will record another log in the same situation (7000rpm 3rd gear)

    And a friend gave me a tip: set rev limit in dsmlink to 6100 rpm and rev It up to see what the rpm gauge will show... I guess it will be a Nice test
    Buddy2 and rabenne like this.
  5. Buddy2

    Buddy2 Proven Member

    Joined Oct 7, 2013
    Helsinki, Europe
    Yep thats a really smart idea. I bet your gauge is just off.

    351  9

    1992 Mitsubishi Eclipse GSX
    awd · manual · 1G DSM

    156  0

    1992 Mitsubishi Eclipse GSX
    manual · 1G DSM

    635  8

    1995 Mitsubishi Eclipse GST
    fwd · manual · 2G DSM
  6. DSMPT

    DSMPT Proven Member

    Joined Jun 12, 2014
    Japan / Mexico, Arizona
    There is a similar case. Check the link below.


    Drag Race Build 2K  3

    1990 Mitsubishi Eclipse GSX
    awd · manual · 1G DSM

    Street Build 2K  4

    1998 Mitsubishi Eclipse GSX
    awd · automatic · 2G DSM
  7. polverari

    polverari Proven Member

    Joined Jan 29, 2018
    São Paulo, South America
  8. polverari

    polverari Proven Member

    Joined Jan 29, 2018
    São Paulo, South America
    Sorry for my delay, I've been busy for the past few days doing a brake upgrade here haha
    Well .. I recorded another log in the same situation (speeding up to EXACTLY 7000 rpm in the cluster gauge)
    This time the result was this:


    That is ... In the SAME EXACT SITUATION, the log this time marked a much closer value (I see no problem with a 300rpm margin of error if I am at 7000rpm, but 900 rpm difference was absurd.)
    I don't know if it was a punctual problem, I don't know if it was a momentary reading error, I have no idea. The fact is that I just changed the coil for a new one and the reading was this.
    I hope the problem is solved, I admit that I don't have the patience to work on the panel / capacitors / pointer gauge just to resolve this 300 rpm difference


    P.S - I know 0.66 lambda is too rich, im working on tuning yet xD

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