So let’s start with the good news. I insulated my coolant return hard pipe and it appears to have done the trick. While I haven’t tested it under load, I did a cold start and let it idle until engine was warm. CLT went from 66F to 180F and MAT went from 62F to 66F. Much better than before!
The bad news is I still haven’t figured out the cause of my random sync loss errors. I captured a data log of the warm up cycle and it showed 3 sync losses for reason #2 (missing tooth at wrong time). After it was warmed up I did a composite log.
From my observations, the sync loss at the very beginning is the normal sync loss everyone experiences during the first revolution of the engine during cranking as the MS3 figures out where the crankshaft is. Once it sees the missing tooth on the crank trigger wheel it’s good to go. However, subsequent sync losses at 3906ms, 15505ms, 20260ms, 26453ms all look exactly the same. The cam and crank signals patterns appear to be fine though, so it’s a mystery to me. Could it simply be an excessively rich mixture causing misfire? Or could there be something else going on?
See DNMakinson’s Seemingly random Sync loss thread. His setup was similar to mine and his “cure” was to ditch the MS Labs WBO2 CAN Module and just use the analog output from the Innovate LC-2. I don’t think I’d be happy with that solution but I might have to give that a try as I am running out of ideas.