1.6 TPS mod
 

I've found the bmw throttle position sensor but it didn't have a connector with it. I'll be trying to find a connector for it today at a local salvage yard but in the case that I don't I was wondering if it was possible to connect a 93 auto tps sensor to a 93 5 speed throttle body. I'm assuming it's not a direct swap and that I'd have to drill into the 5 speed throttle body or replace the whole thing with an automatic throttle body. Just wondering though.

Its pretty involved.....
http://www.mx5nutz.com/forum/index.php?showtopic=1311

I started to mess with a variable tps transplant. I have a tps from a 95 KL V6 626 which would bolt up using a large O-ring as a spacer since the bolt holes line up, but the damn thing rotates the wrong way. That said, the last gen protege appears to have the same TPS but it rotates the other way - so that might be a cheap alternative. The only thing that would need to be resolved is the "keying" of the tps to the TB shaft.

A little off topic but I was at the junk yard the other day and found a 323 with an automatic. The throttle body looked a lot like the automatic miata one except it had a smaller throttle plate. Has anyone tried removing the throttle shaft from the 323 and putting it in a miata throttle body? Then just reuse the miata throttle plate and bolt on the TPS. Would this work?

I've also got the BMW TPS without the connector on it. Being a bit creative with crimped connectors, I was able to attach electric wires which I plan on connecting to the stock harness (using flat crimped connectors).

I doesn't look perfect, but the connections feel sturdy... It's also possible to solder wires as an alternative

I've thought about doing that too, but how do you know which pins are which? I know in another thread their labeled by pin number but there aren't any numbers on the unit that I have.

Pin 1-black wire-5volt in
Pin 2-shielded wire-ground
Pin 3-yellow wire-signal out
Pin 4-ground
Pin 5-WOT switch
Pin 6-Closed switch

See diagram below for pin locations relative to center "T"

Ben, feel free to add [code] tags around the diagram in your post in the MS FAQ sticky to clarify the diagram ;)

OK, that makes perfect sense. the post I was looking at from Ben was a little different. Also I've actually been searching all over the forum for this as well, I know that the stock sensor on my car has a red wire, a green wire, and a black-light green wire. I've only seen write-ups on here for other tps sensors that have those colors for wires. Which pin goes to which wire exactly?

I'm guessing that the red wire goes to pin 1, the black wire goes to pin 2, and the black-light green wire goes to pin 3. Would this be correct? I don't have the wiring diagrams here so it's just a guess.

I can't remember the colors on the stock wires. You can take a look at the wiring diagrams here, but I don't remember anything being non-intuitive.

Has anybody tried the TB from an auto Protege LX, Escort GT or Tracer LTS? They all have variable TPS, the TB looks exactly the same (all BP engines) and they're dirt cheap. I was going this route but apparently the 1.6 MkII link doesn't use variable tps input. :doh:

I was looking into this option before I did my bmw tps doo-dad, but never could get a straight answer about whether they were a variable TPS or not. It ended up being easier to order the bmw tps than it was to find time to get to the scrap yard.

They are.

This is how I wired mine... so it must be correct ;)

Yep - protege guy in the MS forum is using an auto protege LX TB and variable tps. The only thing that "appears" different are which way the "tubes" are pointing - nothing the right hose couldn't fix. For <$40 for the complete TB, it seems to be a good solution.

Got the megasquirt/tps sensor installed. The bmw tps sensor was truly a direct swap. I juryrigged some sockets for pins 1-3 and took off the old sensor and put the new one on and screwed the little bolts back in. Red wire to pin #1, black-lime wire to pin #2, and Lime-white wire to pin #3. Megasquirt still needs adjusting though, but tps works perfectly.

So any auto BP car (escort gt, protoge etc.) has a easy swap variable one? Thats good news, my local u-pull-it has hundereds of those cars.

no. Auto BPs have an entire TB with TPS that is believed to be swappable. I don't think anybody has tried it. But there are several on car-part.com for <$40 for the entire assembly (TB, TPS and IAC).

Sometime this week or next week I plan to go to the u-pull-it. What should I look for?

-Pulling counter clockwise and backward
-Correct bolt pattern
-Connection to TB plate

Anything else? Should I check the whole TB or just the sensor? Should be easy enough to check.

I'd try a bit harder to find the Bimmer one. Speaking from experience, it makes things so simple.