I was browsing some archived info here and saw mention of a very
low-tech ECM module that would have come on my truck. Again, it's an
'86 K5 Blazer.
According to what little info I was able to gather, the ECM was
connected to a knock sensor and could monitor ignition timing. The
latter part got my attention.
Is this true regarding its ability to monitor timing (advance)? If so,
is there a way to tap into it or read it somehow to output it to a
gauge to monitor the timing real-time from in the cab?