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-   -   SDS RPM Pulses per Revolution? (https://vansairforce.net/community/showthread.php?t=176828)

majuro15 11-11-2019 06:31 PM

SDS RPM Pulses per Revolution?
 
I'm getting inaccurate RPM numbers on my AFS5XXX screens. I know I can adjust the settings but don't know how many pulses per revolution the SDS ECUs give off? Anyone know? I have the EM-5, full SDS setup.

rv6ejguy 11-11-2019 08:28 PM

3 pulses per crank rev. You can have a 5V signal from pin 12 (green wire) or 12V signal from pin 22 (yellow wire).

Mike S 11-11-2019 08:42 PM

Quote:

Originally Posted by rv6ejguy (Post 1385663)
3 pulses per crank rev. You can have a 5V signal from pin 12 (green wire) or 12V signal from pin 22 (yellow wire).

Is this true for all units, or just the six cyl??

majuro15 11-11-2019 09:19 PM

Thanks Ross! So I am 90% I need the 12V so I have the yellow wires hooked to the EFIS. If I actually need the 5V, would that affect the value the EFIS is reading?

I'll try the 3 setting tomorrow. I did play with that a second today but feel like the EFIS was still reading high.

rv6ejguy 11-12-2019 06:07 AM

Quote:

Originally Posted by Mike S (Post 1385665)
Is this true for all units, or just the six cyl??

4 cylinder systems will deliver 2 pulses per crank rev.

rv6ejguy 11-12-2019 06:10 AM

Quote:

Originally Posted by majuro15 (Post 1385673)
Thanks Ross! So I am 90% I need the 12V so I have the yellow wires hooked to the EFIS. If I actually need the 5V, would that affect the value the EFIS is reading?

I'll try the 3 setting tomorrow. I did play with that a second today but feel like the EFIS was still reading high.

Check the minimum trigger voltage on the EFIS for the tach pin you're using. The 5V could be too low to give an accurate reading.


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