[Bleeker]

Hi all,
I´m looking for the Map scaling of a combined Mikuni Sensor Unit called MAQS, it looks like this:

bandit1250 tps 1.JPG (124.58 KiB) Viewed 5828 times

bandit1250 tps 1.JPG (124.58 KiB) Viewed 5828 times

It contains IAT, TPS and MAP Sensor.
Where the first two are no problem, I´m struggling to get the MAP values.
I found some information that the Voltage at ambient pressure should be 3,81V, which also matches my actual measurements.

Can one of you give some information on this?
Or do you have an idea how to gather the data?

[PSIG]

I don't have that info here, but as most MAP sensors have a linear output, you only need one more reference to set it in Speeduino. If you can't find that, and you have a vacuum gauge; hook it to a known vacuum source or any running engine manifold. Read the gauge and read the sensor voltage at that gauge reading. There is your second reference.

David

[Bleeker]

I have organized a Vacuum Pump now, unfortunately the vacuum is slowly dropping because of a leakage which I couldn´t find, so I can´t guarantee the precision of the readings.
But in case anybody else needs this information, here are a few values:

36,5 kPa - 1,32V
49,83 kPa - 1,82V
63,16 kPa - 2,38V
76,5 kPa - 2,96V
103,16 kPa - 3,93V

Info from the Internet (without guaranty):
101,325 - 3,81V

This kind of Sensor is used on throttle bodies of following bikes: Yamaha YZF125, MT125, WR125, Suzuki Bandit 1250, Husqvarna TE 250,310,450,510
I think it’s even used on many more.

[PSIG]

Running your numbers, I can't get a slope that quite matches. If using the highest and lowest measured, it goes negative kPa at 0V for example, and does not hit the factory spec at 3.81V. With a very small adjustment and rounding, giving 26.5945 kPa per Volt I think it should work well if calibrated in TunerStudio for 0V = 0kPa and 5V = 133kPa; which clips your measured values and also lands nicely on the 3.81V/101.325 factory spec. Please check my math.

Please post all known part number(s) to reference this sensor for future searches.

David

[Bleeker]

Thanks for the hint, this is how it looks in my Excel Sheet with actual measured values and idealised function:

Mikuni MAQS map scalling.JPG (97.48 KiB) Viewed 5732 times

Looks like the values of 0V = 0kPa and 5V = 133kPa will be good.


Unfortunately I could not really find a identification number for the Sensor which makes sense, it seems like those are always supplied along with the throttle body to the OEMs.
I have two of them here but both have a different number, I will post the numbers anyway and also compare if scalling is same.

[PSIG]

Considering that a typical tolerance value for MAP sensors is 5%, this is not splitting hairs. Shift it to 0V/3 and 5V/130 if it makes you giggle. As much as we would like to think of it as a hard-core and irrefutable calculation value, in-fact it is only a relative but consistent reference. This again throws us back to why shared tunes cannot be plug 'n play, and must be re-tuned to your specific hardware. Throw a couple 5% tolerance lines on that graph and let's see how the curves fit.

I had seen a part number when looking for this sensor, but lost it. Good luck finding a reference of some kind!

David

[Glavey]

I know that this thread is more than a year old, but the information given has helped me with my current project; thanks for posting it! I want to add a part number to possibly help others in the future.

I don't have a part number for just the combo sensor module, but the whole throttle body/sensor/IACV assembly part number is 3B3-E3750-01-00.

Mine came from a 2015 Yamaha Zuma 50F. It seems that the part # is the same for the 2015-2019 models.