How to wire an analog TPS to MS in a '90-'93 car.
 

This is for DIY-style Megasquirts, using stock Miata TPSs of various years. The instructions for an MSPNP are in the official documentation.

At the Megasquirt, connect pin 26 (Vref) to the green / white wire at position 2L of the ECU harness, and connect pin 22 (TPS) to the red wire at position 1N of the ECU harness.

Under the hood, cut the 3 pin connector off of the vehicles harness.

For a '94-'97 TPS, assuming you have a pigtail for the new 4-wire TPS, splice the red / black wire of the TPS to the red wire of the car's harness. Splice the green / white wire of the TPS to the green / white wire of the car's harness. Splice the black / blue wire of the TPS to the black / green wire of the car's harness. The red wire of the TPS will be unused.

If you are using the TPS from a '90-'93 automatic car, the wiring at the MS is the same, and the wiring at the TPS is as follows: The red / black wire of the TPS goes to the red wire of the car. The green / red wire of the TPS goes to the green / white wire of the car, and the black / green wire of the TPS goes to the black / green wire of the car.

For an NB TPS, the green / red wire goes to the green / white wire of the car, the green / black wire goes to the red wire of the car, and the black / red wire of the TPS goes to the black / green wire of the car.

This is like the 5th time this has helped me, thanks alot Joe!

Joe you says:
At the Megasquirt, connect pin 26 (Vref) to the green / white wire at position 2L of the ECU harness, and connect pin 22 (TPS) to the red wire at position 1N of the ECU harness.

Ben (from DIYautotune) tell me that in a PNP is, connect pin 26 (Vref) to the green / white wire at position 1N of the ECU harness, and connect pin 22 (TPS) to the red wire at position 2L of the ECU harness.

Confirm???

Someone's got their signals crossed.

Here is the relevant section wiring diagram from the factory service manual for the '90-'93 model years:

http://img02.imagefra.me/img/img02/8...cm_6babf0d.gif

Since we are talking about the retrofit of a TPS into an M/T car, we'll want to focus the the section marked "M/T" and ignore the one marked "A/T", as the former is how the harness on the car is built. You can clearly see that 1N is a Red wire, and 2L is a green/white wire. This is consistent with my on-car observations.

It actually doesn't matter which wire colors you pick, or even which pins they land on, so long as the correct terminals of the TPS wind up at the correct pins inside the MS.

If you follow the instructions I gave above, you will wind up with a correctly wired TPS. I can't comment on the instructions you copied here from Ben, as you only posted the ECU side, and not the TPS side, however the correlation between wire color and ECU pin is clearly incorrect.

Bingo. It doesn't matter which way it's wired, so long as the wiring is correct on both sides of the harness.

I am not sure where the wiring colors came from. Here is how we wire up the 90-93 MSPNP for variable TPS. As Joe points out, the way we do it is not the only correct way it could be done.

How can i see if my Auto TPS works fine??
Tell me which wires i have to look resistence. I tried and didn´t work.

i have in AutoTPS 4 wires:
1. green/red
2. red
3. red/black
4. black/green

Thanks.

I know i have to check and then move the butterfly (TB) to move the sensor. Open and close have diferent values and any position between diferent values.

EDIT, sorry

I have a E34 automatic Bosch variable TPS, so I only have to plug it to my oem TPS wire, like this :

http://myturbomiata.com/journal/albu...mal_VTPS15.jpg


but my question is:

On a MSPNP, you have to do this trick:

http://myturbomiata.com/journal/albu...mal_VTPS19.jpg
Now to mod the MSPNP. Remove resistors R6 and R7.

and

http://myturbomiata.com/journal/albu...mal_VTPS20.jpg
Install two jumper wires.


but I have a MS1 pcb V3.0,

do I have to jump somthing and remove resistors?

R6 and R7 does'nt seems to be the same resistor on both MSPNP and MS1 pcbV3.0....

thanks


http://www.ownerslocker.com/images/l...ight_green.gifsource

the V3.0 board is already looking for the TPS signal, therefore you just need to send the signal back to the MS.

In my writeup, I suggest wiring the harness to utilize the stock wiring harness to send that signal back correctly:

http://www.boostedmiata.com/gallery2...ne_harness.jpg

2L will send back the VTPS signal and 1N will provide a 5vref signal to power the TPS.

Then you just need to attach the wires on your TPS to the oem wires right there inside the engine bay.

ok, I built my harness by following your thread and this diagram:

http://www.alexroy.net/miata/90-93_M...ndalone_MS.JPG

instead of this

http://www.boostedmiata.com/gallery2...ne_harness.jpg


so I just realized that I'm missing 2 wires for my tps to work

Thanks again Brain, soon my MS is gonna be a :brain: assisted lol

I plugged it, but when I calibrate it, I have the same reading at closed throttle and full open throttle,,,,

but I actually plugged it directly to the tps harness

one more recap for the intelegance impaired

remove resistors R6 & R7

jumper TPS, Vref, gnd to the correct pins on the header

is this correct for inside the diypnp?

Good Evening-

Hoping someone can provide the wiring schmatic for the three plugs that go into the back of the MS. Noting some of the commentary above, we know the green/red stripped wire goes to the TPS, but we don't know where to place it in the plug. There are four slots available, and the wire has come out of it's hole. I do know it is a manual TPS, if that might help (1990 Miata). Thanks for your insight. JB

No. R6 and R7 are unique to the '90-'93 MSPNP and should not be used for anything without the MM9093 daughterboard.

how would I go about wiring a 99' miata tps to my 91' MSPNP2??

do you have the pigtail on the TPS?

Yes i do.

black/green to black/green

tps green/red to harness red

tps red/black to harness green/white

So I got it all wired up and I plugged in my laptop to calibrate the TPS in tunerstudio but it doesnt seem to send any voltage to the computer

Let me double check the wiring diagrams.

Try this:

I had you reverse the sig and ground.

tried this with my MS3x and had no luck when Calibrating. Ive checked the wiring on numerous occasions and everythings right. sigh.

Just as note on this topic, I found the automatic variable tps on an escort GT this weekend in the junkyard. Same part number as the miata even though the GT was a 1.8, it still had the 1.6 throttle body and not the 1.8 style. I haven't seen that option documented anywhere yet.

interesting.


but i dunno what the deal is with your wiring. You can check it the old fashion way to make sure you have the proper singals. The MSPNP2 docs say that's all you need to do for the tps: wire it in.

Ive tried 3 different vTPS' from auto TBs. They all work fine off the car and the OHMs check good. My values in TS are all over the place. Possible bad throttle body somehow?

Link to decent VTPS option for 90-93s:

https://www.miataturbo.net/megasquir...tps4185-75375/

Back from the dead!

I've been struggling with the TPS signal on Oregonmon's VVT swapped 1990. After following the VVT swap thread's instructions:

https://www.miataturbo.net/engine-pe...athread-80469/

I found the TPS wiring instructions for a 1.6 lacking. So I googled "90-93 miata vtps wiring", and this thread was the first non-m.net result. Followed these instructions to the T, as I was using an NB TPS:

But later on Braineack's instructions say that the 5v ref and signal are swapped from Joe's description

Even later still, Braineack confirms this wiring:

My original wiring was complete junk, resulting in random close throttle values from -10%-10%, and barely touching the throttle would result in it going upwards of 25% negative, before finally going positive around 50% throttle. Obviously this made closed loop idle and accel enrichments nearly impossible to tune.

If you're having these same issues, try following Braineack's wiring, it's correct, Joe (for possibly the first time every) is wrong.

For the life of me i cannot find a pigtail for the vtps. Can anyone help me with this?

So is there a way to avoid all the wiring, by just buying another style of tps and making that work?

I don't mean no wiring at all but like.... not messing with my ecu. I'm a baby about that

why would you have to mess with the ECU?

which "the" vTPS?

In FM's 1.8 swap guide, it says this:

"The 1.8 throttle position sensor (TPS) won’t talk to the 1.6 ECU, so you must retain the 1.6 TPS (if you retain the stock ECU)."

Is that simply assuming if you just bolt NB TPS on and don't rewire as outlined here?

meaning this upgrade is pointless unless you have an aftermarket ECU that knows what to do with the signal.

Got it, thanks.

Since this thread is back from the dead - I'll tack on a question I've been chasing. I just switched to a 4-Wire Auto TPS on my 1.6 and followed the wiring diagrams you all so graciously put out there for us! However, I have voltage creep on the sensor now. It will bottom out when I come off the throttle, and that is where I calibrated my TPS lower limit. However, if I let it sit there for a few minutes, it's voltage creeps up and the % showing in the TPS will creep up as well. After about 5 minutes it will be as high as 35 or 40%. Any ideas on how to diagnose/fix?

FWIW: I had it on a bosch variable TPS without this issue, but that throttle body exploded at the track so I swapped in the whole assembly from an auto car. 1.6 racecar.