--also posted in the haltech section--
This is for those who want to run a standalone, but retain the S4 OMP and TPS and can't find the supposed (and rarer) S5 throttle body.

With a little modification, you CAN use an S4 STOCK TPS and OMP with a standalone. I know, I did it, and it works perfect. I wanted to do an official write up and take better pics, but I will jump the gun.


See that little crescent shaped cam against the TPS plunger? That's the trick. As it rotates, it pulls away from the plunger, but very gradually. The stock sensor is operated by a little lever that lets go of the plunger wayyyyy before full throttle. That's why the stock won't work without a little modification (but how did mazda get away with this?). I drilled a new area on the S4 TPS mounting bracket so I could move the position, and keep it in line with the crescent cam I mounted on the shaft. Again, notice I have the OMP connected.

You can make the crescent cam by cutting a small piece of metal into shape. You need it to become "thinner" as it rotates forward. This way it will allow the plunger to retract, thus giving you the continuously varying TPS reading.


================================================== =============
And before all this, I had made a simple OMP lever by bending some little metal pieces and mounting them on the shaft using the E6K tps. So with a little patience and tinkering, you can make it work either way.

 

AFM coupled with an intimate knowledge of their motor.

Do you have a specific radius and offset for the cam? Or is it not even circular?

 

Intimate knowledge my ***; They managed to make the only electronic fuel injected car that floods itself. OK kidding aside. Yes mazda did it on the S4, but I'm wondering why if it worked it changed on the S5? I'm thinking with experimentation, one could even get it to work bone stock. I did have it hooked up that way, and the car ran, but had some extreme bogging/hesitating obviously.

Nothing specific on the cam. I wanted to make a better writeup, but I jumped on it. I also need to reiterate I modified the TPS bracket so I could move it. I imagine when people try to make their own, they will need to move the TPS to whatever position works. Unfortunately, the car is on hiatus until winter here in the NE passes. I would ultimately like to make a template that people can simply print out and cut to shape on whatever stock they can find.

Below is a silly mspaint diagram of how this works. As it rotates, the cam gets "smaller" and pulls away from the TPS. Don't worry, if I ever make a print out, I'll do it in CAD.

 

I want that template if you ever post one up. No rush here though.

 

^will do after winter is gone. I'm done with this thing and my wallet/paypal needs a break.

 

so how does your S4 TPS read in the haltech output? full clean sweep 1-100% matching the pedal?

didn't change on the s5. the full range is just for the eOMP.

 

question is, why?

both S4 and S5 OEM throttle position sensors are pure garbage strapped to a plate with a few wires pointing out of it to appear to be a functional sensor for more than 30 seconds. they're probably the worst potentiometer reliability wise in the history of automobiles(i'm hardly kidding either).

i have a bunch that test fine off the car but fail on the car, toss them in a bucket and test them later and they pass, put them on the car and they work fine(as if to laugh at you like little gremlins). some day i'm going to just find an easy GM replacement and smash them all with a hammer for fun.

 

Reads 0 - 100% fulls weep matching the pedal.

Correct, it didn't change on the S5, but when you use an S5 TB on an S4, you use the TPS the EOMP reads so you can get the 100% sweep



Why? Why NOT? Everyone said it doesn't work and you can't do it. I did it. It's for those who want to retain the stock mechanical OMP. I don't feel like premixing, even though I drove a pathetic 700 miles in one year. Also, it's for those who can't find this magical S5 TB/TPS everyone said you have to use. Besides, I did make it work with the haltech/GM TPS. Look at the other picture. Either way I solved the problem. And hey, this stock TPS works.

 

From K2rd

 

^The issue wasn't the electronics/wires. The haltech (and probably any other standalone) can read any sensor. It's strictly a mechanical issue.

 

I used beefhole's s4 TPS pioneering as a starting point for my Custom Haltech TPS solution. I hardly recommend people following my path though since it requires BOTH s4 and s5 throttle bodies AND Tps's

basically what I did was take my stock (s4 TII) Throttle body off, and buy a s5 TPS and an s5 TB (NA or turbo, it doesnt matter).
Then I took my TPS off and removed it from its bracket (it's held on by 4 little metal tabs that can be bent off with a small screwdriver)
I took the FULL range TPS off of its bracket the same way. you have to cut the wires off to separate this TPS from the narrow range one.
I put the s5 TPS on upside down on the s4 bracket.
then, I took the bolt on my TB that holds the OMP lever on apart and removed some of the spacers that aren't needed anymore off.
I then did the same thing to the s5 TB, and removed the cam that the s5 full range TPS rests on off.
I then put this cam onto my TB and lined it up with the new s5 TPS on the s4 bracket.
I had to tap a new thread into my TB to get it to line up, but you could just bend the bracket or make your own or whatever, as long as the cam is touching the TPS and the TPS moves throughout the whole range of throttle motion it will work.
then you solder the s4 plug onto the wires from the s5 TPS and you're good to go.

I did this because I had all the parts already, and an s5 NA TB is only $20. This setup is (surprisingly) super clean and looks almost exactly like beefhole's setup when it's done.
I used the full range TPS because it has better resolution, but the s4 tps will work just fine, and its almost the same procedure to use either. I also got to keep my OMP and my already modded TB, and it only took me a few hours to do this whole procedure.

I did encounter a slight hesitation in off-idle situations because the full range TPS is not designed to work during idle, so the cam has a flat spot. It's hardly noticeable though if I'm honest and doesn't affect driveability very much, if at all. That's the cam's fault though, not the TPS.

Series 4 TPS
-Orange - (+5V)
-Green/Red - Signal
-Black/Red - Ground

Series 5 TPS
- Brown/Black - Ground
- Brown/White - (5V+)
-Black/Green - Signal (Full range)

Haltech -- I think... somebody correct me if I'm wrong
White - Signal
Orange - 5V+
Black - ground

 

they didn't! the car uses the AFM as the primary load, and the TPS is really used for detection of idle condition, and running the ACV.

same as the haltech, actually. the haltech doesn't need the TPS AT ALL for ANYTHING. the only thing is uses it for is detecting zero throttle, and thus decel fuel cut, and the acceleration enrichments.

 

So it does use the TPS for something

There is no reason NOT to have throttle pump unless you like hesitations and poor response. Zero throttle/fuel cut is handy for well, cutting fuel and not wasting it. Plus it makes a fun crackle when the fuel kicks back on during decel.

EDIT
I realize this thread is getting old. Silly me (all winter long) never took the cam off for 5 minutes to trace an outline for anyone to make their own. Sorry about that...

 

I did exactly the same thing as you described for my MS, and IIRC the full-range plunger on the S5's is the same, resistance-wise, as the one on the S4, they're just actuated differently. It works, and gives the full range nice & smoothly when you're sitting still, but at high RPM or boost it jumps around about 2-3%, just due to the plunger literally rattling on the cam. This is enough to trigger deceleration fuel reduction, which is definitely what you don't want in boost. I'd eventually like to get a GM-style TPS to hook up, but since I really only use the TPS for idle control, over-run fuel shutoff, and boost control targets, I can live with it for now.

 

^ I did not experience the rattling you described on the dyno even at 8000 rpms... maybe your TPS is bad? or maybe the dyno is too smooth?
The full range and the narrow range are different part numbers. And guess what else? the narrow range on the s5 is the same part number as the s4 tps, so those are the same, but the full range is different.

With regards to the cam:

I used one off of an s5 GXL because the cams are the same for the NA and turbos.
Basically just slip that cam off of the donor TB and put it on yours.
Bam, no machining, and you know the shape is perfect. You also dont have to worry about it slipping because it's machined for the flat spot on the TB bolt.

I tried to make my own... and I did... and it worked... but I didnt have enough confidence in it to try and drive my car with it.

 

Power FC works fine with the s4 TPS btw.

FD TPS solves the problem if you switch to an FD UIM and TB.

see:

https://www.rx7club.com/attachment.p...1&d=1242967490

 

Jesus.... Christ.... Thank you.

I'll be standing next to you with a 2 lb sledge as well. I've ALWAYS thought the plunger type TPS mazda used was horrendous. When they changed it to the 3rd gen style (as most cars have) I was happy to see someone finally "got it".

 

Did you ever take this off and measure it?

 

talk about a bump. Sadly, I did not. Nobody took much interest in this. My "pure garbage" TPS is still functioning fine. And if it craps out, I have 2 spares so I'm not worried...
I may get to it tonight, this weekend will be bad (weather wise) for me to do anything.

 

i see. you posted this on one of my threads, i was curious to see how you did it, im not running omp, im jus having issues with the plunger being non-consistant.