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Failed Ignition Coil - Need a replacement

CD.

Active Member
I have a Light Speed Plasma II+ ignition system for the top plugs on my O-360 A1A. It uses two PVL 356 100 ignition coils. One of the coils failed today and only one output works on that coil; so the plug for #3 cylinder does not fire. I did troubleshooting to positively narrow down my issue to that coil.

I thought I was going to buy it at the auto parts store, but that doesn't appear to be the case. I can't find that specific coil to purchase or an equivalent to utilize in place of it. Does anyone have a recommendation? Or can please point me in the right direction? I need to replace it ASAP... or my OSHKOSH trip may not happen. :eek:

Thanks so much!
chad
 

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I have a Light Speed Plasma II+ ignition system for the top plugs on my O-360 A1A. It uses two PVL 356 100 ignition coils. One of the coils failed today and only one output works on that coil; so the plug for #3 cylinder does not fire. I did troubleshooting to positively narrow down my issue to that coil.

I thought I was going to buy it at the auto parts store, but that doesn't appear to be the case. I can't find that specific coil to purchase or an equivalent to utilize in place of it. Does anyone have a recommendation? Or can please point me in the right direction? I need to replace it ASAP... or my OSHKOSH trip may not happen. :eek:

Thanks so much!
chad

Scroll to the bottom of the page.... http://www.lightspeed-aero.com/Products/Accessories.htm
 
Thanks to everyone for all the information. :) Apparently the original coils are made from Unobtanium. :confused: I have ordered the newer coils and and a bracket from Lightspeed Engineering. I'm paying for expedited shipping, so hopefully I will receive it this week, install it, and test it so I can still head to Osh Friday morning. :D
 
So I went back and looked at my EIS data and found when the coil failed... you can see #3 EGT suddenly climb about 200deg. Sorry about the poor capture.. I just took a picture of my computer screen :rolleyes:
 

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Maybe not the coil...

So I went back and looked at my EIS data and found when the coil failed... you can see #3 EGT suddenly climb about 200deg. Sorry about the poor capture.. I just took a picture of my computer screen :rolleyes:

And yet no corresponding spike on EGT #4...

In the instance of a failed coil in a wasted spark system such as LSE, you would lose two cylinders, not one.

By any chance did you pull the LSE fired plug in #3 and verify that its showing 4-5K ohm? How about the ignition wire for LSE plug on #3 -- does it measure 50 ohms/foot or so? How about the coil itself? What's the resistance between the high voltage towers? What's the resistance between the fast-on terminals?
 
Agree with Brian Decker
I've flown over a thousand hours behind an LSE and the only failure I had was
installation induced.
In my case it was a loose spade connector that started to arc a bit and eventually lost contact and stopped working all together.
The issue was not visible at least not until I tried to pull the spade connector off and found the offending issue.
 
I initially thought I had symptoms of a bad spark plug. Thought it was going to be cut and dry simple. When I was trying to determine what my issue was, I basically went through the following steps ... running the engine each time and monitoring my EGTs. Each time I turned off my left mag (Slick) the #3EGT would take a dive and the engine was rough... like it was running on 3 cylinders. Left mag back on and the EGT would climb back up.

I first swapped plugs between cylinders 1 & 3.. the plug looked fine, but I didn't measure the resistance... still high EGT on #3
Just for grins I swapped the plugs on 2 & 4.. (to possibly indicate if the EIS may have been looking at the wrong cylinder)... still high EGT on #3
So then I checked all the connections and re-connected everything (spades and ignition wires)... still high EGT on #3
I then swapped ignition wires with #3 and another cyl from the other coil.. still high EGT on #3
Then I swapped the coils... The high EGT went to #1, #3 went normal.

Resistance between the high voltage towers is 8.39Kohms
Resistance between the high voltage towers and either the pos or neg connection was in the Mega ohms... I can't remember the exact value.
 
Chad,

There’s a small chance I have an extra one in the hangar. I will look tomorrow. Please send me a PM with your number. I’ll call or text you after I confirm whether I have it or not. Where in Alabama are you? I’m in Georgia near Peachtree City.

Jerry
 
And yet no corresponding spike on EGT #4...

In the instance of a failed coil in a wasted spark system such as LSE, you would lose two cylinders, not one.

By any chance did you pull the LSE fired plug in #3 and verify that its showing 4-5K ohm? How about the ignition wire for LSE plug on #3 -- does it measure 50 ohms/foot or so? How about the coil itself? What's the resistance between the high voltage towers? What's the resistance between the fast-on terminals?

Not sure that is the case. While the coils secondary winding is connected to both outputs, that doesn't necessarily negate the potential that one of the internal connections from the post to the winding is compromised in such a way that current is limited only on that one post. It would behave just like a compromised ignition wire - only one of the plugs not sparking.

Larry
 
Not sure that is the case. While the coils secondary winding is connected to both outputs, that doesn't necessarily negate the potential that one of the internal connections from the post to the winding is compromised in such a way that current is limited only on that one post. It would behave just like a compromised ignition wire - only one of the plugs not sparking.

Larry

I agree, it's possible that one of the legs has become disconnected internally -or- there is a crack in the insulation that's causing one leg to flash over to nearby ground instead of taking the higher resistance path to/through the spark plug.
 
Back in business!

The coils came in this afternoon (1 day late due to UPS; 2nd day air became a 3 day delivery). I installed them along with the new mounting bracket and she ran perfectly! As a result, she is all back together and now packed up and ready to leave for OSH in the morning!

Thanks everyone and see you there! Just look for the ALABAMA flag flying... that'll be me!

chad
 
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