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1. On the Dsub connector, the wire on pin 15 is for the wideband signal, and I'm guessing that the wires on pins 1-4 are for the TPS signal - which pins on the toyota TPS do the wires go to?
Did I not include a little diagram?
#1 is 12v out.
#2 is Ground out
#3 is Sensor Ground out
#4 is o2 in.
#15 is probably has nothing mating it. I reserve that for the EBC.

These can be used to wire up your LC-1 and input the wideband.

I'd wire the TPS back through the factory wiring at the TPS connector. You'll need to add a 5v jumper wire inside the case to power the signal and cut off one resistor.


2. You set up the MS to use a wideband, and I'll be using an LC1 right before the cat to get the tuning done. I've also got a narrowband o2 in the stock location - is this now superfluous? I've run LC1 a couple of years, and am wary about it being my full time o2 sensor, as I've already had one Bosch sensor failure. It makes more sense to me to get the tune sorted out with the LC1, and then use the narrowband for day to day closed loop operation. Thoughts on that? Would it just be the software setting change in MS, or would there be a solder change required?
Once you are running with the LC-1 you have no need for the NB. You need to unplug from the factory wiring if you have both installed (they both wire to the sam einput). I wouldn't ever use the NB in any operation.
 
Discussion starter · #22 · (Edited)
Brain - No, there wasn't a diagram, but hey np, you just told me what would have been on it, right.

Over in the other thread, 90R was saying that one could splice the connector from a 94-97 mx5 TPS connector to the oem 1.6l TPS harness and just plug it straight in, skipping the IDL pin on the toyota TPS.

Based on FSM's of both cars, the diagram would look like this.

****EDIT - my diagram was wrong. see post below.

Though no one could say if it required the changes to the MS Pcb you mentioned. I'm guessing that if you say it needs it, it needs it. I searched on miataturbo but couldn't find any pics of the resistors/jumpers needed. Does a guide exist?
 
Discussion starter · #23 ·
Based on looking at the wiring diagrams of the 90-93 5spd and auto TPS, and the 94-97 TPS (which even shares a plastic connector with the toyota TPS), and reading joe perez's tutorial here,
I'm confident that I know how to wire the TPS end of things. And the diagram above is wrong. Here is the amended diagram.




So now all I need to know is how to mod the megasquirt PCB. There was discussion of that in the mturbo thread, but it was on old hardware, and the resistors/pins are no longer in those locations.

Hopefully this is something Braineack can show us, and then the whole TPS bullshit can be put to bed for all of us with the AE1*1 ITB's.
 
I think you got it.

Inside the MS unit, there will be a 1K resistor betwen 4L and 4D, snip that out.

Along the bottom row of the mainboard there are a bunch of holes that the jumpers form the connector board are going to. Locate vref (should be between 12v and 5v) and use the extra red wire and solder a jumper from that spot (vref) to 1N.


That will send 5 volts through the spot labeled POW.
The TPS signal back to the MS will go through the spot labeled IDL.
The ground will come from TL.

Just make sure to splice accordingly.

I would have added the jumper wire for you, must have slipped my mind that you mentioned going vTPS. I leave the power wire out so in case someone doesn't go vTPA with a 90-93 the **** doesn't hit the fan. If the connector stays in place the 5volts actually ground out and the injectors tend to lock open.
 
Braineack i bet you build like a million MS's since you repaired/rebuilt mine but do you remember if i had to do any re-wiring on mine . It was for a 94 , I have the print out you sent with it and it doesn't call for any wiring just some setting up using the computer .

I'm getting ready to swap motors into a cleaner shell and figured it would be a good time to do the ITB install .
 
I feel sad cause I can't even remember. But no I wouldnt suspect you'd have to rewire anyhting, it was probably just a few wires I needed to move around, 90-93 and 94-95 wiring is almost identical.
 
is anyone running ae101 itbs with a megasquirt ecu that has a map I can use for mine as a base? it's a mk1 1.6 also can you let me know which ms you are using thanks :)
 
Your jumping the gun ryosuke , the whole point of this thread was to help each other out . As you can see here there isn't any maps posted because most haven't finished there builds/installs as of yet .

I should hopefully have my 1.8 running by the end of December with the Jenvey ITB's and a DIYPNP rebuilt/built by Braineack . I'm crossing my fingers as i'll be doing a swap and wiring all while working 60+ house a week and its getting cold here in Va (USA) .
 
ah i thought some guys had finished their builds not to worry ah dude you think its cold started snowing today! my miata is tucked up for the winter and for its itb build
 
Your best bet for a base map would be to use DIYs base map they ship out with there PnP units. My car started first try with that map and I ran with it for a few weeks with no issues until I finally got the car on the dyno. It's conservative enough that you won't break anything and has all the engine variables already there so it's just a matter of plugging them in to whatever version MS board you're running (I don't think maps translate well across different version boards, I may be wrong).
 
Your best bet for a base map would be to use DIYs base map they ship out with there PnP units. My car started first try with that map and I ran with it for a few weeks with no issues until I finally got the car on the dyno. It's conservative enough that you won't break anything and has all the engine variables already there so it's just a matter of plugging them in to whatever version MS board you're running (I don't think maps translate well across different version boards, I may be wrong).
oh right didn't realise the base map that came on it was good enough to run the itbs aswell, tbh with the ms I'm unsure if its mspnp or diypnp thats the needed since I will be running both tps and map sensors
 
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