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Another E/P mag question

Mike Ice

Well Known Member
I have an E and a P mag and I want to use an Electronics International Tachometer with them.

Is anyone using an EI tachometer with E/P mags?

Have you discovered any issues? What were they?

Thanks,

Mike
wiring, firewall forward
 
The install manual for the E/P Mag shows a couple of ways of using the pulse that comes from them. Either use the P lead with a resistor or use the #6 output ( I think ) from the plug and set up the tacho to count the pulses.

We are using the extra lead into a Dynon 120.
 
Mike,

The Dynon EMS D10 has two tach inputs. In my set up, I connected one lead to each P-mag. That way the EMS tach does not drop to zero when I turn off a P-mag.
 
FYI, The Pmag continues to output a tach signal on the tach output even when completely turned off. I have my tach wired to only one pmag tach output and it never drops out on run-up check.
 
Emag does stop sending when off

I was RPM "Blinded" until I hooked up the PMag Tach lead when the EMag was powered down.
 
FYI, The Pmag continues to output a tach signal on the tach output even when completely turned off. I have my tach wired to only one pmag tach output and it never drops out on run-up check.
Is this true when grounded and power is pulled, as per the Bob K. drawings?
 
EI R-1 Tach Problems with P-Mags

Resurrecting this old thread in hopes that someone can help me diagnose tach issues I am having with my RV-8 running dual P-Mags on an IO-360-M1B.

The tachometer reads 0000 until you run the engine up to a high idle -- I estimate about 1200 RPM (by ear) -- then it bounces around between 500 and 900 and continues to show that until you run the engine up to about 1700. There it begins to become more accurate and stable (though not perfectly stable). From 1800 to about 2200 it is almost perfectly stable, though it will occasionally bounce down to zero while I pull the prop back in a low RPM cruise. I have an Electronics International R-1 tach.

The airplane acted like this since I bought it (with the current setup). I discovered that both P-Mags had tach wires going back to the instrument and I disconnected one from the right mag after reading in the installation manual that you should only use one mag for the tach signal, but the problem remains.

I chose to disconnect the lead at the tachometer because the tach wires go through the firewall and then disappear into a giant maze of wire bundles and I cannot easily see the back of the tachometer. Does anyone know how I can tell which setup was selected by the person who installed the P-Mags? I.e. how do I know what to look for if the resistor method was used. Or, how do I troubleshoot within the instrument if the "count the pulses" method was used.

Otherwise, does anyone know what might be causing this behavior with my tach?

Much appreciated,
Dan
 
Resurrecting this old thread in hopes that someone can help me diagnose tach issues I am having with my RV-8 running dual P-Mags on an IO-360-M1B.

The tachometer reads 0000 until you run the engine up to a high idle -- I estimate about 1200 RPM (by ear) -- then it bounces around between 500 and 900 and continues to show that until you run the engine up to about 1700. There it begins to become more accurate and stable (though not perfectly stable). From 1800 to about 2200 it is almost perfectly stable, though it will occasionally bounce down to zero while I pull the prop back in a low RPM cruise. I have an Electronics International R-1 tach.

The airplane acted like this since I bought it (with the current setup). I discovered that both P-Mags had tach wires going back to the instrument and I disconnected one from the right mag after reading in the installation manual that you should only use one mag for the tach signal, but the problem remains.

I chose to disconnect the lead at the tachometer because the tach wires go through the firewall and then disappear into a giant maze of wire bundles and I cannot easily see the back of the tachometer. Does anyone know how I can tell which setup was selected by the person who installed the P-Mags? I.e. how do I know what to look for if the resistor method was used. Or, how do I troubleshoot within the instrument if the "count the pulses" method was used.

Otherwise, does anyone know what might be causing this behavior with my tach?

Much appreciated,
Dan
Hi Dan, As Gash mentioned in the other thread, it might be a loose wire. While looking at that, you may want to consider installing a device to monitor your pmags, and make sure that they are configured right. This might also help with the other issue you mentioned. There are two systems that I know of on the market, the eicommander.com and the enginebridge.com. With either of these devices, you will really know what's happening in the ignitions. I also find the team at emagair to be very accessible for questions like this both via email and phone, and they have extensive experience troubleshooting installation errors. Please let us know what you find!
 
Dan,

Not enough information. Getting a RPM signal from each pMag to an EMS is dirt simple so perhaps you can cover a few basics.

So start with:
- Are you sure you are getting your RPM signal from the pMags and not an old school tach drive?
- Some EMS units require a resistor in series with the P lead tap line if using a standard mag. Perhaps when the builder installed the pMags he left this resistor in place.

Carl
 
Solved

I got in touch with Electronics International today. Somewhat disappointed, though it is a fairly simple answer and simple fix:

By providing my serial number, they were able to look up and inform me that my R-1 Tach was built to receive tach signals from traditional magnetos. From EI:

“Hello Dan-

Your R-1 will need to be returned for modification to work with the electronic ignition. The 12V signal is not nearly enough to trigger the R-1 currently. The internal boards need to be replaced. The flat rate cost to do so is $125.00, plus shipping. If you would like to return the instrument, please follow the link below and complete the online return authorization form. Having done so, our system will generate a RMA number for you to reference.

https://iflyei.com........

If you have any additional questions, please let me know.”

So I’ll probably end up doing that. Good opportunity to fix the 2650 “redline” and mysterious inexplicable yellow caution band that was also artificially set by the builder which has always driven me up the wall. There is no reason for either of these on an IO-360-M1B swinging an MTV-12-B. It makes me wonder if this was an old tach from another airplane he had sitting around in a box on the hangar floor when he was completing the panel.
 
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