UPDATE to my posts #20 / #29 - I went with my gut and simply ordered a new Pedal/TPS. And that was it.

I took the car out again at one point after my posts above, and prior to ordering the new pedal, with the Sprintbooster disconnected, and the issue arose again in full-crapola; no power acceleration even with pedal to the floor, lagging several seconds with no feedback, limp-mode, all the symptoms. That convinced me to simply order the pedal, and even if it weren't the issue, at least I'd have that in my surplus parts inventory for what seems to be the inevitable a rainy day, yet it was absolutely the fix.

A couple of things to note:

Once installed, I went through the throttle reset procedure (again); after that, the pedal's responsiveness was MUCH better than it has ever been these past 5 years I've owned the car. That makes me think it was somehow devolving or incrementally getting worse all along if that's possible. The reason I got the Sprintbooster in the first place was because I didn't think the pedal was as responsive as it should be, and felt there was a lag in the call-time. Not ever having had a Crossfire SRT-6 before, I didn't have anything on which to compare it - and when asking others online about it, I don't think they could appreciate exactly the degree of lag that I was expressing, and assumed I was describing what would be the usual for the car and simply calling it the nature of a fly-by-wire set-up.

I have now, and have had, many classic pre-1973 cars and my daily driver happens to be the same. So I'm more used to the instant feedback of a cable based hook-up to a carb with immediate response. Now with the new pedal in, the Crossfire mimics that more immediate connection to the throttle better than it ever had.

The car is also no longer needing such constant nursing and travel of the pedal's range to maintain highway speeds, nor do I even need to barely press it to accelerate from say 65 to 80. Equally, at 80mph, I only need to hold the pedal partially down and fixed in one spot, with no need for bouncing the pedal to keep it in the wanted speed range; that should have been a sign right there something was wrong.

Lastly, over the past few months I noticed the car was ever so slightly, nearly undetectable, but seemingly searching for an even idle, whether cold or hot, and whether a cold day or hot day; it idled rougher than in the past. It was very slight, but there. With the new pedal in, the car now idles a whole lot more even, smoother, nor detectable rise/fall in the idle.

On swapping it out; there is much discussion about removal of the washer, but 2 things to make that easy: 1) After removing the retaining nut, I attached rare-earth magnets to the back of the 10mm socket to evenly lift up the washer while pushing the base of the pedal toward the front of the car. The latter seems to be key to making the removal easier. This allowed the washer to clear the bolt and its threads. 2) Once up and angled, then I removed it the rest of the way with a telescoping chaser magnet.

Also, since my original pedal-pad is still like new with only 35,000 miles on the car, I swapped out the new rubber/stainless slip-on pedal-pad portion from my old one to the new pedal, which will allow me to have a nice new rubber/stainless pedal pad replacement in the future if I ever really rip off or tear/wear those rubber nibs on the pedal.

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