Got this done today. Bad news is the TPS GM part #17106680 that I had ready is not correct. As discussed some other places, 17106680 operates in the opposite direction. The correct part number for GM injection 4 cyl Esprit is 17106681. Only the last number is different. I don't know who maintains the various online Esprit parts interchange lists, but if that's you please update with the correct number for the next guy.
Good news is that both are very common, available at most auto parts stores, so it did not hold up the job. The TPS is prrobably the cheapest thing on the car.
The other good news is that the replacing the TPS fixed many problems on my car. I have been struggling with an abrupt off idle that jerks the car when you are trying to feather the throttle in a turn. I did several other things earlier in search of that problem, including replacing the injectors (which it ultimately did need). The TPS replacement virtually eliminated that problem, at least to the extent you could expect from a 1980s design computer system.
The other big thing that happened is that the car really woke up on the top end. Apparently my secondary injectors were not actually firing due to the TPS not giving a high enough signal. Rode home tonight, the car is now an absolute rocket as it always should have been. When the secondary injectors hit, its like the afterburner on a jet. I get the normal Esprit kick when the turbo comes in at the bottom, then another kick at the top. I always thought this particular car was a bit doggy on the top end, but now it accelerates so fast I have to watch out for the rev limiter in the first three gears.
I've always been amazed how the Esprit responds to engine and chassis being tuned just right. You could say the same about any car, but on the Esprit, very small changes make a big difference. Last week I commented here how a 1/2 degree change in front camber changed the character of the car. I've been lucky enough to drive many of these cars over the last 30 years, at least thirty different cars. Only three of those I kept for personal use, the rest were for resale or customer service in the 1980s/1990s. Few of them are set up right because the owners don't realize what's missing, but if you're persistent they all can deliver that Lotus feel. If the previous owner of my car drove it now, he would not recognize it.