PROBLEM SOLVED on 9/11/22
Pickup placement was the issue.
I purchased the engine with 450 hours on it. When I installed the engine I noticed that the tach pickup coil was really loose. I have no clue as to why an A&P would remove it when he pulled the engine. I tightened it up after adjusting the gap and went on my merry way. At some point like hour 3 I started to "mag" checks. Not sure why I did not do that earlier in the garage, but anyway when I did do a mag check just before a flight I got like a 750-1000 rpm drop! The engine ran so well that I decided to take the risk and go flying. I did notice that #3 and #4 were running hotter than #1 and #2. #4 would bounce off the limit. I just chalked it up to odd airflow. I tried a bunch of tests to find the mag issue, but I got somewhere quick when I swapped the 2 6-pin input connectors to the CDI boxes. The problem stayed with the same switch. That to me meant the everything else down stream was probably fine. I next tested and tested more still. First the mag kill lines and switches after many, many tests, they were found not to be the issue. Next I swapped the two stator supply lines to the 6-pin plugs. The problem stayed on the same switch. Ok, I then moved onto the trigger coils. All of their resistance values kept coming up good, even when shaking them. I still thought that it had something to do with the coils or harness being that it was a 2008 engine and the SS wrap looked damaged. I laid down my $1000 ducks and installed the new harness using the Heavy Service manual and pics of the setup before I had taken the harness off. I started it up and to my massive disappointment, the problem was still there. I hit the forum up a bunch times since with questions and replies. All good ways of learning more about my setup, but I was stuck. I had Nada.
I then contacted both Lockwood's man, Dean and Leading Edge Airfoils guy, Brett. They suggested a few tests. Some were new to me and some weren't. Again, more learning. Dean suggested that I try pulling individual leads off of the coils to see how the engine reacts. Sure enough one coil that I pulled made no difference. Excellent!
But the harness is new and the gaps were correct. I also made sure to install the harness using the pics from the previous harness's install. The Heavy Maint manual really is NOT very helpful here. It's drawings do not actually show how the coils are to be mounted. So for two more days I just sat and stared at the engine in my garage.
Today while writing up my coil test finding to both Dean and Brett I noticed that the coils were not really centered over the timing tabs on the flywheel. The triggers on the #3 cyl side were aligned with the taller tab, although the 3/4 B coil was not dead centered on it. The triggers behind the #4 cyl side were different. The tach coil and the B1/2 coil both triggered off of the lower, straight out tab while A3/4 triggered off the taller tab. That dawned on me as be odd that only the tach and the B1/2 coils rode on the lower tab while both A1/2 and B3/4 coils run off the taller tab. Again the manual to me anyway did not say which tab fires which coils. Maybe I just missed it. I don't know.
BAM there was my answer. The B3/4 coil needed to be aligned with the lower tab, not the taller tab. I quickly changed the trigger's placement like a boy opening presents on Xmas. Ta da! ALL FIX!
I wish that I really checked that issue out before buying a new harness, but really if I did not pick up on the trigger alignment issue before I still would have flagged the one coil not working and so I would have purchased it anyway.
My dramatic story should now be closed. And not only that, but hopefully my hot #3 and even hotter #4 issue will now also disappear now that its actually firing.
Thanks for everyone that helped me understand how all of this works. I documented this solution in the hopes that someone else will find it helpful in their bug hunting.
Whew, after a month of this crap, I cannot wait to go fly.
Mike
