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How to hook up analog output of any Air fuel meter to the Yuminashi stand-alo...

6935 Views 11 Replies 7 Participants Last post by  hobbycaptain
Today i decided to experiment with my analog output to see if I could get it to work with the stand alone ECU. To my surprise it works great. This is great news and is really easy to hook up.

First take your analog output wire from your AF meter (most have one), in my case the yellow wire coming from the back of my NGK AFX and plug it directly into the plug for the o2 sensor. I just used the female end of a bullet connector which works great.

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Next go into the yuminashi software under the setup tab and then click on "oxygen sensor characteristics setup".

Once this screen pops up enter the values provided by the manufacturer of your Wide band AF meter to define the parameters. Make sure you go from 5v to 0v from left to right, which seems backwards, but is how it needs to be done. Afterward enter the corresponding AF ratios to those voltages.
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I used this chart for mine:

Once you are done press "enter" on your keyboard to send the data to the ECU. Now the meter will not only read your current AF ratio, it will log the data in the AFR monitor tab by automatically putting the values into the table making tuning way easier.

Here is an example with the engine running, the engine is cold here and i still need to adjust the enrichment values under the enrichment corrections tab so it runs leaner when the engine is cold, but this gives you an idea of what it can do.

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I am loving this ECU and and its capabilities. Ill make a video on how to use the software soon and get it posted.

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I figured this thread would be good to bump up for those using the API/Yuminashi standalone.... I'll add some of what I know for those that may be curious.

I too am running this ecu, and plan to use it with a wideband hooked into the factory O2 signal (once I purchase one just for my bike). Glad to see others thinking like that!

This ecu does not require resetting or tps learning. It does however require the user to configure min/max tps voltage through the software. I recommend inputting values just enough to have the tracer bottom and top out, rather than what is displayed as min and max. This has worked best for me! (I have found that typically .05V less than and greater than the min/max respectively, works best.)

This ecu only operates in open loop, unfortunately.... Fortunately though, the software does log the mixture input, as Snakeibf posted. Easy enough to make changes as such.

EDIT: Another noteworthy apect of this ecu is IAC control is not very good. It does seem to control it, but the logic is not stable if it is indeed controlling it. The FinBro kit I have included a throttle body with an IAC solenoid (CBR150 throttle body?), I do not use it. I have a much more stable idle with adjusting the idle jet on the left side of the throttle body, after setting a base idle with the throttle plate.

Also, after translating the ecu manual somewhat, it does specify that "mode 1/mode 2" is indeed alternate maps, made available by placing a jumper on the 2-pin lead of the ecu. 93/110 or e85? Low/high boost?! Options are plentiful with a switch on it.

I will release my map here for those interested, for 93oct, once I permanently mount a wideband to verify my tune.
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so if i have the 160 touring kit with he yuminashi ecu. I recently got a PC V & Autotune. when i go back to the stock edu it runs like shit, When i run the yuminashi and the Power commander, it idle at 1800-2000. I even had Dynojet on my computer, to no help i should say. its impossible to find someone who knows what they're doing with the Dynojet. I think i'll just take powercommader off, i had much less trouble. i mean, shit suddenly my battery dies out of nowhere. where are the techs that no what the fuck they're doing,?

The PCV and WBC are designed to run with the factory ECU. If you run the Yuminashi ECU with the PCV, you will need to use a custom tune. As far as the WBC for the autotune feature, it may be able to correct fueling but it will not correct ignition timing for the updated fueling (or so I understand? I am not very familiar with PC's).

Another thing to add, I will amend my first post - the Yuminashi/API ecu offers no IAC control. I left my IAC hooked up (I'm guessing the finbro kit includes the cbr150 throttle body, as the usdm units do not have an IAC assembly) to see what it would do, but it is not a stable control IMO. I have disconnected it and used the throttle screw (small philips head on the LEFT/Stator side of the throttle body) to adjust idle. The idle adjust screw on the throttle plate itself (right side/clutch side) will also alter your TPS voltage and will require ECU/TPS relearning upon adjustment.

I'm currently looking for a fuel screw or some alternative for that to adjust on the fly.
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we have read this already in some other threads, must not be everywhere. has nothing to do in this thread, its a complete different theme.

what i see - nobody else has ever tried pcv + autotune with Yuminashi ECU. why should one do that ?
either use honda ecu with pcv + wb2 or tune yuminashi ecu manually by your own.
i am sure dynojet did not try and test their hw together with yuminashi, so, maybe it works fine, but maybe it does not work also.
but, don't grumble around that nobody knows anything about the pcv - you are using a non certified setup.

There is really no benefit to running both as the Yuminashi/API ecu is completely programmable. The only thing I could see worthwhile is using the standalone as a cheaper alternative to replacing the factory ecu if a new ecu is the only option available.

Although the autotune function is nice, there's no reason not to use the factory ecu for control with the PCV.
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