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-   -   PMag Leads are Loose (https://vansairforce.net/community/showthread.php?t=185610)

ChrisMcC 08-08-2020 08:32 PM

PMag Leads are Loose
 
My PMag leads (at the mag) are not confidence-inspiring. They slip on, but do not have the comforting "snap" fitting like at the plugs. On take-off roll today, one came loose, the engine began sputtering, and I aborted the takeoff.

Is there a way to more securely attach the leads to the mag?

Thank you!

Scott Hersha 08-08-2020 09:18 PM

I agree, it’s a weak connector that is used on the Pmags. Do yourself a favor and tin the ends of the wires that slip into the connector. The screw clamps on the connector squishes the stranded wire, and tinning the end first prevents that and makes a more secure connection. You can really crank down tightly on those screws if you do it this way, without breaking any of the ends of the strands.

Toobuilder 08-08-2020 10:30 PM

I think the OP is talking about the spark plugs leads on the coil tower. A bit of vasaline on the boot and a conscious effort to seat the boot as far as possible on the tower (rather than the terminal) will help. There are millions and millions of cars with this coil/wire connection and they don't fall off.

If not, and he's talking about the primary wiring connector, then crimping a brass tube/ferrule on the end of the wire gives the screw something to bite onto without creating the brittle segment of wire solder can cause.

Kyle Boatright 08-09-2020 05:20 AM

If the wires easily slide on/off the coil, you've got wear in the system. Either the wire ends, the coil posts, or both. I don't exactly remember the tactile feel you should get (maybe two light clicks as a wire goes into place), but I noticed this issue on my the last condition inspection and replaced both the wires and coil to correct the situation.

isosceles 08-17-2020 02:43 PM

emagair service notes
 
Did you check emag air service notes?

https://emagair.com/service-notes/


Quote:

Plug Wire Terminal – Coil Connection

Importance – High.

Background: We have recent reports of certain ignition leads having reduced retention force at the coil termination on the back of the ignition...

Carlos151 08-17-2020 03:10 PM

+1 for checking with Emag
 
Last year I ordered a new pMag with a wire set. Then I received a notice from them that some of the wire sets were shipped out with weak connectors that would not snap into place on the pMag or the plugs. After calling them, they had me send my set back in and I soon received a new set of plug wires at no cost. Give 'em a call, they're great to work with.

DanH 08-17-2020 03:35 PM

1 Attachment(s)
Be cautious about using a lubricant on plug boots. Although it tends to make them air tight and moisture proof, it can also allow the boot/connector assembly to rotate slightly on the coil post due to vibration...the boot doesn't grip the tower or plug as dry silicone would. I've seen some really worn connectors, as well as things like spark plug caps with grooves cut in them.

The p-mag coil is a Ford part. E-mag owners are unlikely to change it for the previous style, which is electrically equivalent, but for those going with an EDIS-base system, the early coil uses wire caps with positive retention.
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Larry DeCamp 08-17-2020 04:25 PM

Just something to consider
 
Based on past input from the forum, I use Fuel Lube as a dielectric lubricant for Pmag plug boots and it is very hard to get them off and they are clearly moisture occlusive, just a thought.

Doug Rohrer 08-17-2020 07:28 PM

Another Loose Lead
 
To add another data point, I had a Pmag lead fall off at the mag end on my new engine. Did not notice it because misfire was masked by the other Pmag firing the other plug. I also found a loose, but not disconnected lead on the other Pmag. I will be calling Emag about this. I believe my leads were made in the suspect time period.

Doug Rohrer 08-21-2020 01:18 PM

Update
 
I contacted Brad at Emagair and explained my problem. He quickly agreed to send me two replacement wire sets at no cost. Because the coil ran for a while with the wire disconnected, he said the coil is now suspect and he is sending a replacement coil as well. Great customer service.


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