My trusty TPS201 died after about 30K miles of faithful service. The TPS201 saga can be found here:
Is my TPS201 OK?
Because I wanted to get this fixed RIGHT NOW, I went to the zone to get a replacement. Low and behold . . . no TPS201s in stock . . . I'd have to wait a couple of days. Apparently, whatever car the TPS201 goes on is now too old for the zone to stock replacements. Same story at O'Reillys when they cross-referenced the TPS201.
Since I still wanted to get it fixed RIGHT NOW, I took the opportunity to see if there was another TPS that was stocked and might work. It turns out there is. Meet the TPS4185 (as used on mid-2000s Kias -- many of which used Mazda B6s and BPs):
It actually has the right connector!
And the right shaft fitting!
Costwise, it's ~$13 more than the current list for the TPS201 ($53 vs. $40 -- at Rock Auto the TPS4185 is $33+shipping). But the good thing is that it can be used without modification so that the lifetime warranty stays intact. I felt that was worth $13.
To use this TPS, there are two minor issues that need to be addressed:
1. The power and ground pins are reversed relative to the stock 90-93 MT wiring harness. Some minor harness surgery is required. The wires that have to be reversed are the Red (+5VDC, goes to pin 1N on the ECU connector) and Black/Light Green (ECU ground, goes to engine block and pin 2C on the ECU connector). I did the surgery in the harness about 3 inches from the TPS connector.
2. Although the TPS fits the shaft end, the Miata's throttle body shaft is too long. So, you either need to add some spacers or drill a hole in the TPS case for the shaft to pass through. I opted to add spacers. This leaves the TPS completely intact so I can take advantage of the lifetime warranty.
Here's some pictures of how I mounted the TPS:
The TPS mounting holes are neither far enough apart nor at the correct angle to bolt directly to the throttle body. This plus the spacing problem means that I needed to fabricate an adapter plate. I made one out of 1/8" aluminum stock using my old TPS as a template:
Here are the parts for the assembly. I trial-fitted the adapter plate and TPS to the car to get the correct angle (you can see my mark on the adapter plate). The adapter plate holes are 3/8" for the mounting screws and 9/16" for the TPS shaft. The TPS shaft hole is exactly centered between the mounting holes. I placed the TPS into the 9/16" hole and lined it up with the mark to create TPS mounting holes. These were 3/8" as well and fit the long aluminum rivets in the picture.
I used a nylon spacer along with two 3/8" aluminum rivet backing washers to space the TPS.
Mounted on the car:
It works perfectly.