Lightspeed Plasma III

My Lightspeed Plasma III (about 3 yrs old) fails to work when the weather gets cold. We did re-wire it last year, so connections are probably good

Anyone have any advice?

Ted Chipps

Rv-10 N498EC

I'd be amazed that Klaus would not be all over that. Have you talked to him?

Mine gave up cylinders 3-4. I replaced the coils, no joy. Turned out to be a dirty/oxidized connector that plugged into the timing pick-up. Plugged/ unplugged a bunch of times and all is well.

330drvr said:

I'd be amazed that Klaus would not be all over that. Have you talked to him?

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I will call him on Monday

Connections??

You need to be sure all those connections are good.

so connections are probably good

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Been accumulating almost 1000 hours on 2 Lightspeed ignitions.
One thing Klaus will tell you is to make sure all your connections are good and tight.
About 3 years into flying my RV-8 I developed ignition problems and after replacing a bunch of wiring it turned out to be a loose spade connector.
The ones that attached to the coil and in my case I had the cables attached to the engine case and bridged over to the coils. The coils seem to have their own
harmonics not in sync with the engine most of the time and even what looked like a very neat installation turned out to be a problem after about 300 hours.
The spade connector was loose enough to cause a bit of arcing and started to corrode the connection. This was not visible until you actually pulled off the connector. Those cables leading to the coils should be looped over the top on the coil and attached to it just before connecting the spade, this way the assembly vibrates in unison.
So, check those connectors as well and be sure all is good and tight.
Good luck.

Klaus has an unpublicized (last time I checked) mod out on some of the P-IIIs. Some of the chips were not well-supported and would break a connection. Could be your problem. It is a $300 fix if that is the case.

Do you have RG-400 wires? The earlier black coax could be troublesome and short internally.

I made a point of liberally applying clear RTV to the spade connectors where they attach to the coil on top of the engine. 5.5 years and 400 hours still going strong with no issues.

Kent Ashton said:

Klaus has an unpublicized (last time I checked) mod out on some of the P-IIIs. Some of the chips were not well-supported and would break a connection. Could be your problem. It is a $300 fix if that is the case.

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I note this with interest. On my Plasma II+ hard in flight failure (circuit breaker popped and would not reset), calling Klaus he quickly told me how to do a field mod to fix the problem (cutting a cap and a resistor off the board). As I was away from home I choose instead to overnight a loaner box from him while he did "an upgrade" to my failed box - which I paid for. No mention anywhere that an upgrade modification was available or needed. Over the next year or so I paid Klaus for other upgrades and fixes but still ended up with unreliable ignitions. This was several years ago so perhaps things have improved. I don't know. I do know that the pMags I installed to replace the Lightspeed ignitions seven years ago have been flawless.

Carl