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P-Mags losing their timing

S

SteveHRV7

Member
I have an IO-375 engine with dual P-Mags. On two different occasions my timing has been lost on one of the two P-Mags. Doing a mag check causes the engine to stop when that mag is selected. The engine stopped because the mags were no longer timed correctly - one was firing about 60 degrees later than the other mag. This happened because (as I found out after talking to E-Mags) running the electrical system on a battery charger while I was learning the avionics scrambles the timing. The P-Mag manual warns about this. I reset the timing and all was well for the past 3 or 4 flights.

Today it failed again at run-up. I have not done anything including using a charger since the last failure. The timing of one mag is off about 60 degrees, just like before.

Has anyone had this problem? I will give E-Mags a call tomorrow but I thought I'd see if anyone else has had this problem.
Thanks!
 
Curious as well

Steve,
I can't add to your data, as I haven't experienced the missed timing. I did read the warning and talked to Brad at EmagAir about the potential as I keep my Odyssey PC680 on a Battery tender 24/7 when not flying. My solution is to always pull the breakers (Ships power to PMags) as part of my 'Post Shut-Down' checklist. (Side note: Many people expressed concerns over cycle rates of CBs, so to counter this, I bought an extra CB and it goes in my travel kit. That along with a phillips screw driver and I can change one out in about 2 minutes.)
Luckily to date, I haven't had any issues doing the above. I too like to turn on the Master and/or Avionics while still attached to the charger. This step prevents the possibility of missed timing from occuring.

Will be following to see if others are having the issue and how they are combating it.

Dan
 
Steve, those of us who were early adopters of the P-mags saw this but they fixed the problem with a software upgrade.

Are you running 113 or 114 P-mags? If running 113's, have you had them back for the upgrades?

Either way call Brad on Monday!

BTW, when you charge your battery, is your P-mag powered up? It just seems odd to me that your charger would zap the P-mags. I have non-standard wiring which isolates my P-mags from the master buss.
 
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Me too!

It has happened to me as well. She would backfire on the e.mag. I re-tiimed It but the LED no longer works. Brad said he would send me a replacement electronic board to see if that fixes it but I haven't got around to it yet .
 
interested in hearing more. I have dual Pmags and have left my battery on a trickle charger on 1 or 2 occassions and have not had this problem.
 
Interesting.

I have dual P-Mags in my -4. I often put a trickle charger on the battery if I believe it might be a couple of weeks before I fly next. Sometimes, I turn on the master, though the P-Mags are on a separate switch that is not typically energized when on the charger. I have not had any problems, but it sounds like I have a new "worry bead". Please keep us posted.

Thanks,
 
Wouldn't turning the PMAGS off after shut down preclude this?

Have dual PMAGS, watching this thread.
 
Monitoring the mags

Reading over the many years of forum posts pertaining to engine operating issues, diagnostics and monitoring you could conclude that there is a need for an ?ignition monitor.? Bill Repucci?s Electronic Ignition Commander(EIC) goes a long way to close that gap. I wasn?t initially motivated by the need to monitor the ignition system rather I was a bit anxious reading some of the posts regarding the P-mag issues. Since I have duel P-mags I invested in the EIC mostly for the peace of mind factor it offers. The additional benefits are the mag set up and monitoring features (the real purpose of the system). My RV8 just turned over 100 hours flying in some very hot Florida wx and now I feel pretty much at ease with the mags but I do monitor them.

The EIC has a zillion screens that show more detail than I can remember but use only two: the tach screen and the TDA screen. The TDA screen gives you a real time look at the ignition status from your mag to the plugs. The other screens allow you to select timing maps etc. I use the map with the 39 degree upper limit (don?t have my book in front of me so I don?t know if it is A or B). Like the beer commercial, ?I don?t often monitor my mags but when I do I prefer EIC.?

And no I don?t have any financial connection with the EIC company or Repucci.
 
Not a problem yet...

I frequently leave a 10 amp charger or trickle charger my RV7 with a single P-Mag (114 Series) / Slick set up. It is an isolated charger circuit and the Master is usually but not always off but the P-Mag power is always off.

151 hours with no problems at all. So far, the P-Mag has been perrrrfect!
 
Manual timed mine

I have 2 pmags and use a battery tender 24/7 and never had an issue. However, I manually time them to TDC first. Then use the blow technique. This way the software pointer and the default pointer are set to the same place, TDC. If if jumps from the software pointer it goes to default which is the same spot.
Seems to be rock stable.
 
RV7AV8R said:
I have 2 pmags and use a battery tender 24/7 and never had an issue. However, I manually time them to TDC first. Then use the blow technique. This way the software pointer and the default pointer are set to the same place, TDC. If if jumps from the software pointer it goes to default which is the same spot.
Seems to be rock stable.
Click to expand...

Can you explain the two pointers in more detail please?

Bevan
 
RV7AV8R said:
I have 2 pmags and use a battery tender 24/7 and never had an issue. However, I manually time them to TDC first. Then use the blow technique. This way the software pointer and the default pointer are set to the same place, TDC. If if jumps from the software pointer it goes to default which is the same spot.
Seems to be rock stable.
Click to expand...

I wanted to verify with E-mag before I replied to this post and they confirmed my understanding of how the P-mags are programmed.

There is no ?default pointer?, as described above.

Back when the early E & P-mags were experiencing lost timing marks E-mag implemented a ?default pointer? but once they resolved the lost timing bug, they removed the ?default pointer?. So if you are running 114 P-mags there is no ?default pointer? and if you have had your 113 E & P-mags back for the software upgrade (This upgrade came out a few years back, nothing current), there is no ?default pointer?.

All John did was accept the timing mark, wherever that happened to be when the P-mags were manufacture.

The ?Blow in the tube? method of timing is the method to set the P-mag TDC mark.

PS. If you don?t know if your 113 E & P-mags have been upgraded, contact E-mag with your serial number(s).
 
Update to my original P-Mag thread

For all who were interested in this thread -
I contacted Brad at P-Mags. Because one of my P-Mags has lost its timing information on more than one occasion without an obvious reason (i.e. using a battery charger) he requested I remove them both and send them back to P-Mags for repairs or replacement. I will keep you posted as to the final results.
 
N941WR said:
I wanted to verify with E-mag before I replied to this post and they confirmed my understanding of how the P-mags are programmed.

There is no ?default pointer?, as described above.

Back when the early E & P-mags were experiencing lost timing marks E-mag implemented a ?default pointer? but once they resolved the lost timing bug, they removed the ?default pointer?. So if you are running 114 P-mags there is no ?default pointer? and if you have had your 113 E & P-mags back for the software upgrade (This upgrade came out a few years back, nothing current), there is no ?default pointer?.

All John did was accept the timing mark, wherever that happened to be when the P-mags were manufacture.

The ?Blow in the tube? method of timing is the method to set the P-mag TDC mark.

PS. If you don?t know if your 113 E & P-mags have been upgraded, contact E-mag with your serial number(s).
Click to expand...
Thanks for the correction! Here I thought I was being real smart. Oh well.
 
N941WR said:
There is no ?default pointer?, as described above.
Click to expand...

Thats unfortunate. I was banking in it after reading the old posts. I guess I will have to look elsewhere for my EI when I upgrade in a few years. I have no intention of relying on the blow in the tube software setting method.
 
From the Installation & Operating Guide, page 5, item 5, Note 2:

Note 2: DO NOT power the ignition ON if/when you have a battery charger connected to the buss. Some chargers are designed to pulse the battery with high voltage that can damage electronics.

I read this to mean that with the master switch off, charging the battery is fine. If the master switch is on while connected to a battery charger, I would think the PMag switch ("ignition") should be off (or pull the PMag breaker.) How would the PMag be subject to damage with the PMag switch or breaker off?
 
rzbill said:
I have no intention of relying on the blow in the tube software setting method.
Click to expand...

Huh? Sounds a little prejudicial, unless you have tried it and found that it doesn't work. It takes me about 20 seconds to set/check timing on our two dual-P-Mag airplanes. Setting traditional Slicks with a buzz box takes quite a bit longer, since every time you tighten down the nuts, the timing changes slightly, and you have to play with it.

There's nothing wrong with "not liking" a method if you've tried it and found it has issues, but give it a try first...
 
mikehoover said:
From the Installation & Operating Guide, page 5, item 5, Note 2:

Note 2: DO NOT power the ignition ON if/when you have a battery charger connected to the buss. Some chargers are designed to pulse the battery with high voltage that can damage electronics.

I read this to mean that with the master switch off, charging the battery is fine. If the master switch is on while connected to a battery charger, I would think the PMag switch ("ignition") should be off (or pull the PMag breaker.) How would the PMag be subject to damage with the PMag switch or breaker off?
Click to expand...

The on/off switch does not remove power from the EMAG, it only turns off the ignition, so pulling the breaker is the only way to isolate it.
And keep in mind many people, I think, wire it direct to the battery ala' Bob Knuckles or even Light Speed recommendations. So turning the master off will not isolate it, pulling the breaker is the only way to electrically disconnect. Its a pitfall for sure, the need to remember to do that if ever you charge the battery.
I think I'll make a placard to remind me and put it on the battery.

Tim
 
tim2542 said:
The on/off switch does not remove power from the EMAG, it only turns off the ignition, so pulling the breaker is the only way to isolate it.
And keep in mind many people, I think, wire it direct to the battery ala' Bob Knuckles or even Light Speed recommendations. So turning the master off will not isolate it, pulling the breaker is the only way to electrically disconnect. Its a pitfall for sure, the need to remember to do that if ever you charge the battery.
I think I'll make a placard to remind me and put it on the battery.

Tim
Click to expand...

This depends entirely on how it is wired. I have my P-mag wired to the output side of the battery contractor through a fuse which is de-energized whenever the master is off. The only time the p-mag can be energized with the master off is above about 700 or so RPM at which point the internal generator supplies the power. This is independent of the p-lead switches. I would not wire a p-mag directly to the battery as this is a sure fire way to have a dead battery if the plane sits for any length of time off a charger. They left the units off their current draw chart in the install manual but if the units are AMPS then you'd kill your PC680 in about 7 days. If units are mA then you'd kill it in 70 days if wired directly to the battery. I've kept mine on a charger almost 100% of the time for the past 2.5 years. Charger connected directly to battery through a fuse - no issues.

break break

The Blow in the tube method of timing is brilliant application of the KISS principle. It is nothing more than using the MAP pressure sensor as a switch. Eliminates the need for extra hardware, wiring, tools, etc.. Sure beats the method used for normal mags and certainly easier than using timing lights, magnets, and voodoo like some of the other EI.

unsolicited .02
 
For the first year I had my dual Pmags wired to my battery buss and often used a trickle charger without problems. However, I once forgot to shut off the Pmags after a flight and the draw drained my PC680 after a week.

At my last annual I rewired my Pmags to my e-buss. The are now powered up/down with the master.
 
Ironflight said:
Huh? Sounds a little prejudicial, unless you have tried it and found that it doesn't work. It takes me about 20 seconds to set/check timing on our two dual-P-Mag airplanes. Setting traditional Slicks with a buzz box takes quite a bit longer, since every time you tighten down the nuts, the timing changes slightly, and you have to play with it.

There's nothing wrong with "not liking" a method if you've tried it and found it has issues, but give it a try first...
Click to expand...

C'mon Paul,
Not prejudicial.
I base my comments on the early failures. Some of which are included in posts here on VAF. You may have high confidence in the Emags timing system. I do not yet. Unfortunately to try it I must spend 1.5 aviation monetary units and (in my mind) raise my risk.

If the reported failure modes during during development were simply "it quit", I could live with that. However, the modes included extremely advanced timing. That scares the H*** out of me because it negates the supposed "safety" of a second mag by putting the engine in danger even though the mag is OK.
 
rzbill said:
C'mon Paul,
Not prejudicial.
I base my comments on the early failures. Some of which are included in posts here on VAF. You may have high confidence in the Emags timing system. I do not yet. Unfortunately to try it I must spend 1.5 aviation monetary units and (in my mind) raise my risk.

If the reported failure modes during during development were simply "it quit", I could live with that. However, the modes included extremely advanced timing. That scares the H*** out of me because it negates the supposed "safety" of a second mag by putting the engine in danger even though the mag is OK.
Click to expand...

True Bill - but as you posted, the key was "early failures". They have come a long way in six or seven years - I wasn't interested in testing them back them either, but much success by many noted RV builders/pilots changed my mind.

If an organization refuses to grow, I won't do business with them because they won't last. E-Magair has learned and applied a lot.
 
rzbill said:
...If the reported failure modes during during development were simply "it quit", I could live with that. However, the modes included extremely advanced timing. That scares the H*** out of me because it negates the supposed "safety" of a second mag by putting the engine in danger even though the mag is OK.
Click to expand...
The solution to the lost timing mark has always been to cycle the mags and shut off the offending ignition.

Never once, I have I heard of a simultanious dual failure.
 
Has anyone discussed the method of detection of a PMAG/EMG or for that matter a conventional magneto being mistimed?

In other words having the kinds of displays we have, do you have 100% confidence that you could tell the difference at taxi, take off or in the cruise if your magneto/pmag or whatever had changed by say +/- 5 degrees?

No prizes for guessing where you could learn this either...just had to jump in first before some wise crack does?

This is a serious thing. It helped kill 8 people in Whyalla several years ago. :(
 
RV10inOz said:
Has anyone discussed the method of detection of a PMAG/EMG or for that matter a conventional magneto being mistimed?

In other words having the kinds of displays we have, do you have 100% confidence that you could tell the difference at taxi, take off or in the cruise if your magneto/pmag or whatever had changed by say +/- 5 degrees?

No prizes for guessing where you could learn this either...just had to jump in first before some wise crack does?

This is a serious thing. It helped kill 8 people in Whyalla several years ago. :(
Click to expand...

Check out our EICommander.

We built it specifically to tell you if you have a timing issue with the E/P-mags but it also has a LOT of other functions.

Here is a link to the manual, which explains all of its features.

Here is a sample of the TDA (Timing Divergence Alarm) screen:
TDA%2520with%2520Advance.jpg
 
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RV10inOz said:
Has anyone discussed the method of detection of a PMAG/EMG or for that matter a conventional magneto being mistimed?

In other words having the kinds of displays we have, do you have 100% confidence that you could tell the difference at taxi, take off or in the cruise if your magneto/pmag or whatever had changed by say +/- 5 degrees?

No prizes for guessing where you could learn this either...just had to jump in first before some wise crack does?

This is a serious thing. It helped kill 8 people in Whyalla several years ago. :(
Click to expand...

Exactly.
How does the pilot know that an EI has failed at an inappropriate advance?
High CHT and low EGT maybe? Rough?
How would I react? Don't know. Others got it wrong during the Emag development. I could too.
The second functioning ignition certainly does nothing to help that situation.

I concede that Emagair has improved the products and I may still buy one in the future, but it will be after a considerable time has passed with no (starting today) reports of timing irregularities. The battery charger thing is BS. That needs to be resolved because procedures are always broken at some time or another.
 
I guess you didn't see my post right above yours Bill.

Other than this lost timing issue, I haven't heard of one in some time and I've been tracking them due to my interest in the EICommander.

We don't know why his P-mag failed. It could be that he has the older 113’s and never had them in for the software upgrade. It could be that they were left on while charging the plane. Or it could be something else entirely.

My P-mags are wired differently and do not power up with the master, as described in the manual. Anyone who wires the P-mags differently than the manufacture’s recommendation is assuming they know more than the designers.

While mine are wired in such a way as to be a possible cause of some of the early lost timing issues, I have elected to leave the wiring as is. The reason for this is that not only do I have an EICommander installed to tell me when/if something goes wrong but I am trying to get them to fail. In 448 hours, I have been unsuccessful. That includes using a trickle charger, messing with the timing via the EICommander, and some other tricks we have tried.

Since E-mag Ignitions fixed the software and the trigger magnet retention issues, these things have been rock solid and probably more reliable than a traditional magneto.
 
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rzbill said:
Exactly.
How does the pilot know that an EI has failed at an inappropriate advance?
High CHT and low EGT maybe? Rough?
How would I react? Don't know. Others got it wrong during the Emag development. I could too.
The second functioning ignition certainly does nothing to help that situation.

I concede that Emagair has improved the products and I may still buy one in the future, but it will be after a considerable time has passed with no (starting today) reports of timing irregularities. The battery charger thing is BS. That needs to be resolved because procedures are always broken at some time or another.
Click to expand...

From EIC manual.....

"Care should be taken when changing ignition values. Incorrect ignition values could damage your engine causing engine stoppage which may result in destruction of property, injury, and/or death. It is up to you, as the pilot, to determine the safe operational parameters for your ignition/engine installation and operational environment."
 
Gents, my post was of a general nature and not specific to the PMAG, and sure there lovely device posted above will suit some folk

Bill, yes you would notice a change in EGT and CHT from what is "Normal" for your aircraft.

Advanced higher CHT and lower get, and the opposite for retarded timing.

How many people would be on the ball enough to notice and diagnose this.

You get a chocky frog for being on the ball! :)
 
Bill,
You are correct, I did not see your post. I took a break while writing (totally revised my post) and did not refresh the display when I came back to it. Your EI Commander does address the diagnosis issue. Thanks, I had seen it in another post recently but forgotten about it.

David,
I love chocky.....:D
 
gasman said:
From EIC manual.....

"Care should be taken when changing ignition values. Incorrect ignition values could damage your engine causing engine stoppage which may result in destruction of property, injury, and/or death. It is up to you, as the pilot, to determine the safe operational parameters for your ignition/engine installation and operational environment."
Click to expand...

Yes, that disclaimer is there because the EIC will allow you to adjust the timing curves but not the TDC mark. This can be done in flight or on the ground and we felt that messing with the timing should not be taken lightly

By "adjust", the EIC will allow you to swithch between the A and B curves as well as let you configure a custom curve. it will even let you put in a negative offset for turbo applications.

What we can't do is give you a TDA alam when running two different ignitions. This is due to the different timing curves of each that would cause the EiC to alarm even though the difference is "normal". Heck, the EIC will even alarm if one P-mag is on the A curve and the other is on the B curve.
 
N941WR said:
My P-mags are wired differently and do not power up with the master, as described in the manual. Anyone who wires the P-mags differently than the manufacture?s recommendation is assuming they know more than the designers.

.
Click to expand...

From the P-mag install manual:

5. ?5? connects to your main 12 volt aircraft buss, routed through a dedicated
3 amp switchable circuit breaker (not provided) using 18 gauge wire. If
using a fuse (instead of breaker), use a slow-blow type. The switch
function is needed to test the (P model) internal alternator during ground
run up ? see Operating Notes.
Note 1: Whenever the aircraft buss is powered up, the ignition is ?awake?. It
draws a small amount of current even when not firing the plugs. Use the main
buss switch (or breakers if necessary) to power down the ignitions when not in
use.

I don't see anything in the install manual which suggests having the P-mag connected to a buss which is powered by the master switch is going against their installation advice? The master switch routes power to the buss, the P-mag is wired to the buss trhough a fuse or switable ckt bkr. Am I missing something?
 
RV8R999 said:
...
I don't see anything in the install manual which suggests having the P-mag connected to a buss which is powered by the master switch is going against their installation advice? The master switch routes power to the buss, the P-mag is wired to the buss trhough a fuse or switable ckt bkr. Am I missing something?
Click to expand...
You are correct, that is wired according to the E-mag manual. I was thinking of something / someone else when I posted that.
 
What is the result of sending Mags back

Hi Steve;

What was the outcome of returning the Mags?
 
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