My apologies for not seeing this sooner.I still have the problem with it advancing timing too far. (20 initial and 40 total)
Timing light inaccurate? What light are you using?
Scan tool is probably not in "Road Test" mode. If the scan tool doesn't provide proper resistance between two of the pins on the ALDL, the computer goes into a high-idle mode.I did notice with the scanner plugged in that it idles faster than I expected (1k RPM). That drops down slightly when I put it in drive. When I put it back into park after driving around it started idling at 2k RPM. This higher idle went away if I turned off and restarted the vehicle. All this is with the truck warmed up. Temp was staying between 200 and 210 F.
It's been so long since I've played with that that I don't remember specifics. My scan tool has options for "Codes and Data" which provides the high idle, and "Road Test (C&D)" which doesn't.
I looked up the part number he used, and Autozone shows it as valid for his vehicle.I had an issue with my truck throwing a code 43 right at startup. Apparently there are 2 different knock sensors for these trucks. The one you posted is the white one, which is what I had. I replaced it with the black one and it fixed my issue. This is just a thought
Autozone could be wrong; and he said he removed a black sensor and replaced it with the white one--so you may be onto something.