Thanks for the help guys. I've not been able to locate knock retard in TunerPro RT. Maybe it's missing from my ADX file or I don't understand how to determine it. Can any of you help with that?
There is a "Knock Count" listed in TunerPro and that's what I was referring to. It will increment 2-6 at cold start up, which I understand is normal. Over the long weekend I took it for a couple drives and logged the data stream. It was recording occassional knocks going down the interstate with relatively no grade at around 75 MPH with the cruise set. When I got in the throttle pretty heavy the knock counter would increment 6 to 10 times in a few seconds. But I can not actually hear any knocking or pinging.
I found a test procedure for testing the knock sensor and ran some of those tests this afternoon. At idle and 1500 RPM, the engine does not knock and the knock count does not change. If I tap on the right exhaust manifold, knock count increments every time. That's as far as I went, since the chart indicates the ESC system is functioning correctly.
My timing light is a Harbour Freight special, so I'm not sure how accurate it is. I'm going to try and verify the timing with another light and a piston stop as soon as I get a chance.
I replaced the EGR valve a couple years ago, but I can't remember if I used an aftermarket or Delco valve. I intend to test it and make sure it's working correctly though.
Based on my the data logs, the TPS seems to be working correctly. I'm not that familiar with the MAP and IAC sensors on these trucks, so I need to study up on what I should be seeing from them.
I also intend to pull the plugs and see what they look like and look inside the combustion chambers as best I can with a borescope. Also going to check compression while I'm at it.
I bought a bottle of Techron this weekend that I will put in some high octane ethanol free gas and see what that does.
The throttle body has never been rebuilt and has the original injectors that have never been cleaned. I did ohm them out today though and got 1.7 ohm on each one. They are both spraying what looks like a good cone to me, but I'll probably still send them off for cleaning as soon as I can do without the truck for a couple weeks.