Up next after the "Stumbling Sonoma" is a 2007 Buick Rainier with the 4.2L straight-six.
A replacement engine was swapped in from a 2008 Chevy Trailblazer, and now it cranks but doesn't start.

Turns out to be another unusual junkyard case study...crazy stuff!

IVAN'S PICO WAVEFORMS:
https://drive.google.com/drive/folder...

THINK TOOL PROS:
https://www.amazon.com/dp/B08XXWHQVJ?...

Enjoy!
Ivan