Engine bogging down with any swift throttle change

[JustJeff]

Here's what I've got so far:

I've got timing close, but trailing timing does not line up. Leading is perfect on yellow (white in my case because I powdercoated and repainted the marks) mark, but trailing is off by a bit. It's right around 1/3 of the way between red and yellow.

I tested TPS a few different ways. I tested straight resistance per FSM and did some deadzone. But I see deadzones in every TPS I test in the same general area. I got advice on the other forum about always testing TPS in continuity mode because sometimes autoranging will "timeout" and show OL. Testing in continuity shows smooth figures with no deadzones.

I also tested with voltage as suggested here and that comes up different. I get it set to 1v, engine warmed up, pos lead back probing greed/red wire, neg lead grounded to battery. Idle might be a little higher than 750-800. It was at 900 when I last had it idling and warmed up. I started up the engine to check idle and turn it down a bit and it was perfect between 750-800. I start moving the idle and it reaches about 3.6v and OL and I haven't gotten to 1/3 of the movement. I made a video on my smartphone. I'll upload it once I get home today/tonight.