Ethanol concentration with Series 1? | AEM
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azfiveoh
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Ethanol concentration with Series 1?

Is it possible to use the Series 1 to determine ethanol content is E85 if wired with a flex fuel sensor?  I understand the EMS cannot make on the fly adjustments based on ethanol concentration but it would be helpful to at least be able to see the concentration of ethanol in the fuel.

AEM_NS
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You'd only be able to measure

You'd only be able to measure and see the raw signal which will be reported as a period.  You'd have to know what period equals for flex content value.  Not hard but it won't be something that's viewable in the software.

azfiveoh
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I've wired the sensor output

I've wired the sensor output to T4 on an 30-1400 box.  E85 doesn't vary a whole lot but it would be good to know if the concentration of ethanol is higher, or lower, than the expected 85%.  If I were to take a tank of known E85 and establish a baseline value for the raw signal how would the reported period change based on the concentratio of ethanol in the fuel and where would I veiw the raw data?

Thanks.
 

AEM_NS
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You'd look at T4 Per or

You'd look at T4 Per or period.  0% content is 50hz which is 20ms and 100% content is 150hz which is 6.67ms.  E85 should be about 135hz which would be 7.40ms.  The relationship between content and period is NON-LINEAR.  Take some time to figure out common content to period numbers and you'll know what you're looking at.

azfiveoh
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Thanks for your very detailed

Thanks for your very detailed and helpful response!

azfiveoh
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So I've gotten the sensor

So I've gotten the sensor wired up and am not getting a reading on T4PER.  I've confirmed the wiring is good and that the sensor is getting power.  There is a T4 Off/On setting in the full list that is currently off.  If I turn that on the T4PER reading changes to 131070ms but doesn't fluctuate. Is there something in the software that needs to be activated in order for the T4 input to become active, or do I have another problem?

I also wanted to confirm the numbers you've listed for ethanol concentration.  0%=50hz=20ms, 100%=150hz=6.67ms, 85%=135hz=7.40ms.  By non-linear relationship does this mean that the shape of the curve is parabolic?

Thanks for your help.

AEM_NS
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T4 is technically Spare Speed

T4 is technically Spare Speed and to get T4 to read a frequency input, you need to select the Spare Speed trigger edges.  In this case, try having both Sp Spd Falling and Rising Edge checked on.    

azfiveoh
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I have very little experience

I have very little experience adjusting the speed sensor settings.  How do I make changes to the spare speed input without affecting T3?  Are the T4 parameters accessed via the speedometer settings under the sensors section of the software?
 

AEM_NS
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Go Setup>Sensors>Spare Speed

Go Setup>Sensors>Spare Speed>Options.  

azfiveoh
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As always, thanks for your

As always, thanks for your helpful response!

azfiveoh
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I've played around with the

I've played around with the spare speed sensor settings and still can't get any kind of output to show on T4PER. I've confirmed that the sensor is getting power and properly wired to the EMS. In the spare speed options I have the following settings:
Sp Spd Falling Edge - Checked
Sp Spd Rising Edge - Checked
Cam=Spare Speed - Unchecked
T4 ON - Unchecked **(When T4 ON is checked the reading T4PER reading shows 131070ms and doesn't change.)**
Sp Spd H Sens Below - 0 rpm
Sp Spd L Sens Above - 0 rpm

Have I forgotten something or am I doing something incorrectly?

Thanks for your help.

AEM_NS
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You might need to check the

You might need to check the sensors output with an oscilloscope.

azfiveoh
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I don't have access to an

I don't have access to an oscilloscope. Is there another way I can test the output to the EMS?

AEM_NS
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You could maybe try a

You could maybe try a multimeter that has the ability to read frequency but an o-scope would be the right tool for the job.  Unfortunately we're kind of at the end of what support I can give to set this up.  If it doesn't work, you'll just need to keep messing with it until it does.

azfiveoh
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Understood, I'll keep messing

Understood, I'll keep messing around and see what I can figure out. I appreciate all of your help.

suprant0010
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I used an egt input to rig up

I used an egt input to rig up a fuel pressure sensor, I even scaled the egt fuel correction so the numbers correlate to fuel pressure readings. I could use it as a fuel pressure failsafe if I wanted, but I just use it for logging purposes.

Maybe the same thing could be done for the flex fuel sensor?

azfiveoh
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That's a pretty interesting

That's a pretty interesting idea, thanks for sharing what you did.  I suspect the sensor outputs are different.  Maybe somebody knows for sure who can chime in?

azfiveoh
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AEM_NS, is a pull up resistor

AEM_NS, is a pull up resistor between Vcc and Vout required when using the T4 input on the series 1 box?  If so, that might explain the problem.  If a pull up resistor is installed, does it need to be removed if a Series 2 or Infiniti EMS is installed?

Thanks for your help.

AEM_NS
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Assuming the jumper is set

Assuming the jumper is set for a digital input, it should already be pulled high internally in the box.  That's what the "T" jumpers set: either a pull down for VR inputs or a pull up for digital.

AEM_NS
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Assuming the jumper is set

Assuming the jumper is set for a digital input, it should already be pulled high internally in the box.  That's what the "T" jumpers set: either a pull down for VR inputs or a pull up for digital.