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Posts posted by Mobilelpg

  1. Hi,


    Iceman - Thank you for confirming that the circuit works, once I get my GTR back out this will be one of the first things I do so glad to know there is a confirmed method.

    Adam - Unfortunately I was too late here to actually see the diagram and it is now missing, would you be able to repost it please?




  2. Hi,

    Thanks for the replies and information.
    I want to have accurate control of the Speedometer, currently it uses a converter chip to adjust it from KPH to MPH and this keeps dropping out intermittently.
    There is a way of converting it to MPH inside the speedo head but you have to cut and bridge certain jumpers between 1 and 9 and each one of them tweaks the speed reading slightly so would involve a lot of removing the head, soldering the jumpers then road test against GPS and then adjust again and there is no real information about which jumpers control the reading by how much so could be very time consuming.
    I originally thought just feed the signal to the ECU and let the ECU control the speedo, then I remembered the speedo receives the signal from a VR so I just thought if the speedo is driven by the square wave after the VR signal has been conditioned I could bypass the conditioning chip and drive it directly.
    This would mean I could ditch the converter chip, make speedo adjustments easy and also, it does bug me a little that I can have RPM sweep but not Speedometer sweep.

    It isn't critical as I can carry out the mods to the speedometer but really would like to use the ECU to control it.

    Thanks again,

  3. Hi,

    I am hoping to use my Link G4+ to drive the factory speedometer in my R33 GTR and hoping someone with a more in depth knowledge of the standard speedometer/electronics can help.
    As standard the Speedometer receives an AC signal from the VR sensor in the gearbox, this comes into the speedometer input pin, it then 'conditions' this signal and sends it out as a square wave to go to various other ECU's including the factory engine control unit.

    What I need to specifically know is, is the actual movement of the needle done by the signal direct from the VR sensor before it is conditioned and converted to square wave, or is the needle movement based on the conditioned square wave signal?

    I would like to feed the VR signal from the gearbox directly into the Link ECU as a speed input, and then send a square wave output from the ECU up to the speedometer to drive the needle.
    If the needle is driven by the conditioned signal I could hopefully feed directly to that and drive the needle from the ECU, however if the needle is driven directly by the AC signal from the VR sensor then I would need to convert the Link square wave output back to an AC signal and into the speedometer input.

    Hope somebody can shed some light on this.


  4. Hi,

    Just done a quick bit of searching for you, my Mitchell software doesn't have it and none of my other wiring programs show it either so I cannot put one up on PDF for you.
    However here is a link to the workshop manual for the electrical circuits on an FTO which contains the 6A12 ECU wiring with pin details.


    I just downloaded it and checked and it looks thorough enough for what you need.

    Hope this helps.


    A bit more hunting found this page with ECU pinouts.





  5. I have setup something slightly similar using virtual auxiliaries.

    If the wideband goes leaner than a set amount and RPM and TP are over a certain point it activates a warning light on my dash and starts a timer.
    I then have an overlay table that starts adding fuel based on the timer.

    This works well for me as at the start of the timer nothing happens so during a brief lean spike nothing changes however if it is a genuine lean condition due to something being wrong it will start adding fuel (percent added based on percent lean) and that is only if I haven't noticed that the light has been on for more than a second and reacted.



  6. Hi,


    I did try this but clearly I wasn't rolling enough for it to register for my first gear calibration , as soon as I pressed calibrate it instantly said finished.
    I wasn't sure if the 655.35 gear ratio calc reading at standstill meant it was reading inverted.
    The speed is bang on accurate as calibrated by GPS but I didn't realise it was showing KPH while I was adjusting to show an MPH figure.

    I will adjust the readings so that the KPH is GPS accurate as KPH, then get the car on the ramp and go through the first few gears calibration to see how it goes.

    So a reading of 655.35 at standstill is perfectly normal?

    Thanks again for your quick reply.

  7. Hi,


    This reminds me, when I tried to calculate my gears last time I took my car out, every time I tried it just showed 'Finished' even though I hadn't started moving.

    I completely forgot about it as I do not use the gear in any of my current settings however this reminded to look into it.
    My data shows 'Gear Ratio Calc' as 655.35 the whole time I am not moving, once I start moving through the gears this numbers drops with each gear change.

    Obvious now that it is reading movement when I am at a standstill hence why is instantly states calculating and then finished before I even move off.
    I have posted a screen shot showing the data and my settings, but before I next take my car out I thought it easier to ask, should I be turning off the pull up resistor or changing the leading edge?


    P.S I also need to recalibrate the speed units as my KPH reading is actually showing MPH figures.



  8. Hi,


    Thank you for looking into it for me, really appreciate it.
    I was hoping it would trigger if any cylinder registered noise above the set number, I have a Phormulla KS-4 permanently dash mounted so that shows me if I get any spikes in knock readings so it is not critical.
    The rest of the virtual aux do exactly what I want.

    Thanks again,


  9. I have setup numerous Virtual Auxiliarys to trigger a warning light in my dash etc

    i.e Engine temp over 105 degrees, Injector duty over 80%, EGT over 900 degrees all turn on my engine management light.

    One of the switch conditions I have set is Knock value > 500 to trigger the warning light.
    The reason I have this set is that I have my knock threshold maximum is 500 so I thought if any cylinder peaks higher than this it would turn the light on.

    On a few occasions I have hit the RPM limiter and it has caused one of the cylinders (usually cylinder 2) to trigger well over 500 which is where I have the knock threshold set to, the log registers a few counts of knock from this but never triggers the warning light.

    So my question is, what specifically does the knock switch condition refer to?
    Is it referring to 'Knock level global' or 'knock count global' or something else?




    Virt Aux G4+.jpg

  10. Yes,

    I added my name to the request for 'Save all Logs' and would also appreciate default location.

    On my other Skyline I run an ECUMaster EMU ECU and that has an autosave log file option, the whole time the PC is connected it is saving the data to a default folder, if I forget to save the specific log I can always go into that folder and find the data albeit not specifically named to that particular session.

    I have a feeling that once PCLink was closed the log files have all been deleted but I am really hoping they are stored in a temporary cache file that I could search for.


  11. Is there a temporary folder where all of the log files are stored? (I have checked the Windows Temp folder and they are not in there)

    After a session on the track yesterday I copied the log files from the car PC onto a USB stick to analyze on a bigger screen unfortunately for whatever reason the files have not copied onto the USB.
    I have closed PClink on the car PC so the list of log files is no longer available but I was hoping (praying) they are stored in a temporary folder somewhere that I can pull them from?

    Any help would be greatly appreciated as I had a few occasions where my Accusump kicked in on the Donington Park track, this is the only place where it happens and I would really like to see the Oil Pressure data.



  12. I am using AEM wideband gauges in both of my Skylines (1x standard and 1x failsafe), they have been reliable over the years but....

    With the 0-5v feed into the ECU giving the ECU a wideband reading, there is always a discrepancy.
    My gauge might be showing 14.7 afr but the ECU is reading 14.2, so I adjust the offset to get it perfect, then when the gauge is showing 11.0 afr, the ecu might be reading 11.5.
    So I adjust the offset again and the best I have managed is have it mostly correct at the rich and stoich range, but incorrect in the lean area i.e 15.5 reads 16.0 or 15.0.
    To make it worse the discrepancy is slightly different from one day to the next.

    I have tried everything including the earthing via the ECU sensor ground etc, this is not a Link ECU issue as I had the same issue with Apexi and ECUmaster.

    For that reason alone, I would have and will in the future be opting for a CAN wideband to get rid of this inaccuracy, I want to know that when I tweak the mapping based on the info from my log, that when it says the AFR was at 11.5, it actually was at 11.5 and not in fact 11.2 or 11.8.

    Hope this helps,


  13. What I would like is a cursor that I can freely move around the table (not from one box to the next), with a separate small window which would always show the interpolated value for the position of the cursor.

    I realise I can change the axis of the table and click yes to 'Interpolate table values' to view the interpolation value, but a free cursor with a separate interpolation view box would be great, maybe there is already a way of doing this that I am not aware of?


  14. Hi Simon,


    Thank you very much for your quick reply.

    So just to clarify, if I drive through the range that closed loop lambda is active collecting as much data as possible, then pull over and store to ecu.

    If I then load that file into PClink and compare to the map before the store was made, I would see numerous changes made throughout the fuel table?

    I would go and try it now but I have messed up my back so currently out of action.

    Thanks again and sorry if I am asking for information that is obvious.


  15. Quick tune will require you to be in cell centers it can be set to auto but it is hard to know when you are in a cell with out a passenger.

    The later G4+ Series introduced mixture map tuning which is much better for this type of tuning.


    The other option is to use closed loop lambda and then when you strop driving do a store to the ECU to lock the changes in before turning off the power to the ECU.



    HI Simon,


    I just found this thread and wondered if I could get a little more information regarding your advice to use closed loop lambda and then do a store to ECU before shutting off power.

    So when driving in closed loop lambda, is there a table somewhere that temporarily stores the 'trims' applied? if so can this be viewed on PC Link?

    If you store to ECU before shutting off, does this make the trim adjustments save somewhere for quicker future use or does it make a direct change to the fuel map?

    Very interested ot know what the store to ECU actually does regarding the closed loop lambda.

    Thank you,


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