Again, thank you all for continuing to help me figure out this intermittent frustration and potentially stranding let alone perhaps dangerous situation. Everyone's input is helpful and considered.
"The van that the internet repaired as a community" We may even be able to solve world hunger...
These alternators are externally regulated and are very easy to test (only 2 field coil contacts), if you can't / have no desire you can simply unbolt it and have it bench tested.
I hadn't considered alternator, low voltage or AC ripple for this, I am interested in this as a possibility. Cheers
TPS can be tested with a multimeter too, but TPS can't overheat the coil pack.
After my hours long test drive and observations, I am thinking that my P0171 perhaps may be something else such as the TPS, [or a friend suggested (MAF) but I think that is a different technology to calculate and control injector squirt] contributing to this happening. While I did put a heat baffle as a test a few years ago, over my exhaust cross over pipe that then since become a permanent contraption, AND I do (did) believe that to have had cured the very similar intermittent 'poor running' what ever it was has returned.
Now that you mention it, when I rolled into the driveway the day before yesterday, I left the van running a little rough and I poured a room temperature 20 oz water bottle atop the ignition coil, hoping to notice the engine to start running better as the coil cooled. Alas, no change in idle performance noted. and I was too tired from the day to try to make it around the block.
My belief that my ignition coil was failing when too hot, a few years ago, may have just been my "Analysis Paralysis"
Again, I don't like the lean code and coil pack overheating, it could be a strange coincidence but likely not.
What could it be?
Please help me focus on Lean Code p0171 I am not certain about hot coil. I I now believe that I may have been kidding myself with that BS
fuel delivery (pump/regulator - pressure, filter or injectors - flow)
Now, years ago when this first started happening to me on my road rage spirited drive home while crossing state ( I am sometimes ashamed that I let inconsiderate and offensive drivers get me wrapped around MY axle) I am trying to remember the timeline, but I checked fuel pressure (and I don't remember if it was part of diagnosing this or if I found low pressure or IF the van just outright died on me another time) Perhaps I (and now that I think of it) I remember hooking up the FP test rig two times. I digress... I found a blown fuel pressure regulator in the tank pump assy. Replacement was required and the preferred wholesale parts house was two days for my preferred Denso/Walbro pump assy or they had a Delphi pump assy in stock that day.
The Delphi pump, I did note after R&R was audibly louder than the OEM pump.
Yes, I did also replace the fuel filter 'spider' assy.
Last week when I thought I had gotten a bad fill of fuel and that was what was making this fault start running rough and stalling, I remember thinking, that the pump did sound louder than I had been used to these past few years since replacement.
I intend on returning the AutoZone loan a tool inner tie rod tool kit and borrowing the fuel pressure test kit once again...
emissions controls (overcompensating for o2 sensor defect)
I did replace the upstream o2 sensor BUT I didn't follow the forums recommendation of using a Denso and NOT using a Bosch (or perhaps the other way around) I think I used Bosch, I'll have to research further... [YET ANOTHER time when I kick myself for not keeping a maintenance LOG BOOK in every vehicle glove box to refer to]
No code or reason for the replacement of the o2 sensor other than parts canon to get improved fuel efficiency. I understand (or believed something) I read about the fuel efficiency getting worse over time as the o2 upstream o2 sensor started to age?
Lean running engine will have a different torque 'curve' - it will have easier time with higher rpms (until it burns the valves).
Flying by the seat of my pants??? I have seldom been able to feel much. Though I do feel it when it starts to run rough and/or hesitation.
I should pull and read the plugs, at the very least the front easy ones, as asides from a 20 second idle restart test, it is as it was when I had my trip two days ago.
I know I use a lot of words. Thank you for those who take the time to read all my BS and to those who don't have the time or interest... I do understand.
I am just trying to provide thorough information and observation so YOU CAN HELP ME and also to let folks (both present and future) view my thought process and diagnosis steps. Not everyone has exposure to diagnostic thought logic.