2012 Suburban Misfire #5 drama

[Keiterburb]

my 2010 had a strangely similar issue once, I'd circle back to that bundle of wires near the power steering pump. I've seen a few threads out there on the internet about those wires rubbing through and shorting, and the weird nature of this one feels very similar. Your P219A could also be indicative of an issue with that side's injector's harness. I'd get the pin outs to the ECM and ohm the connector from the injector harness to the ECM and with your meter connected I'm betting you will see the issue if you jiggle that harness by the power steering pump.

Will see about checking deeper into harness if I can find the schematic, shooting power and ground at injector harness and coil were solid? If I find connector and pins on ECM I could take off and shoot Ohm readings looking for jumping around when wiggling harness wear worn. Got noise light for injector plug coming in two days.

 

[Keiterburb]

Definitely looking up CASE relearn and checking if I have capability. I have had battery removed for long periods of time between maintenance, even tried throttle body relearn by cycling key on off 3 minutes on/60 off 3 times then idle for 5 min and drive cycle?? Don’t know if correct but following a video posted.

 

[Keiterburb]

Ran a cheap poor resolution borescope down #5 and could see most piston head with seemingly little carbon build up and no visible damage. Ran crank over and both valves came out and reseated.

 

[Keiterburb]

I was able to figure out how to graph some data. Here’s is the O2 difference after 20 minutes on road and parked at idle.

 

[Keiterburb]

After drive here we’re the fuel trims