On the trip home, I had problems yet again, and when we stopped at Grants Pass for fuel I took the cowl off again to try to diagnose it. This time I checked the coil connections more carefully, and they didn't seem right to me. There was a little noise like strands moving when I wiggled the wires going to the coils (those were my own crimps). I removed the connections and did a pull test, and everything was fine...what the heck is going on?
Interestingly, after doing that, the system performed absolutely fine the rest of the way home. At that point I was convinced I had some sort of contact issue on the coil connections.
I actually had a bout with food poisoning while I was up in Portland, so I was still pretty sick when I got home on Monday. Tuesday and Wednesday I had a lot of work to catch up on, and it wasn't until Wednesday night that I had a chance to head to the hangar and really chase this problem down.
Basically here's what I came up with. As you may remember, I re-wired the coils when I got back from the east coast trip. The fast-on connectors I used were the plastic insulated type, and I have to admit that I bought them in a little multi-pack from...are you sitting down?...Home Depot. I've learned the hard way that not all connectors are created equal. I mean, I guess I knew that to begin with, but I wouldn't have expected the effect to be so blatant.
Here's a shot of one of the coils. What was happening was that the female fast-on connector wasn't making good contact with the male end sticking out of the coil. It's hard to believe, since the things were friggin' on there as solid as I could tell. But it's obvious now that either the material or coating or whatever used on those cheap connectors broke down, corroded, or something. And I think they actually "spread" a little. Here you can see evidence of wear, or possibly even arcing? The voltage going through here is so low I doubt it was arcing, but you never know.
The other problem was that the plastic insulation prevented me from really seeing and confirming the quality of the crimp. In any case, I promptly chopped off those cheap connectors and went with non-insulated connectors, ones that I got from B&C originally. The way I see it, I don't need insulation on these connectors...and if I do, I can use heat shrink or silicone wrap. So much for the plastic insulated connectors. I'm done with those.
In fact, it was those same type of connectors that I had problems with on the RPM sensor originally (the connectors that came from Advanced Control Systems). At this point I'm boycotting plastic insulated fast-on connectors and will use the standard non-insulated ones.
By the way, I'm not talking about no insulation at all...I'm probably using the wrong terminology anyway. The connectors are insulated where they crimp over the wire, but they just don't have the plastic interlocking male/female covers. Hopefully you know what I mean.
I ended up scotch-briting and cleaning the coil terminals to get rid of the wear marks you can see above. The new setup works absolutely perfectly. I've got several hours on it as I write this and it hasn't acted up since.
So why did changing the plugs solve the problem a couple of times? It didn't. It was that each of those times, I also futzed with the coil wiring to make sure it was solid. I'm sure that each time I did that, I jiggled the connectors just right and "fixed" the problem, albeit temporarily. I just got into a pattern where changing the plugs "fixed" it once, so I just kept thinking that was the issue. It's too easy to repeat a working pattern sometimes, especially when you're on the road and don't have a good shop environment or the time you need to be able to really isolate the issue.
The lesson learned here is that yet again, the coil wiring is the most finicky element of the system...and my own work is the only questionable aspect of the system. Electronic ignitions get a bad rap, and I think most of the time it's due to stuff like this. You gotta admit that there's something to be said for just going with mags and keeping it simple, stupid. But at this point I still refuse to use two mags...I gotta have at least one electronic ignition. A lot of people argue against EI systems, and I appreciate that perspective. I do believe, though, that once you rule out installation errors, EI systems do a pretty darn good job.