Ok I am starting the wirinng on my car tonight and was wondering where all you guys mount your megasquirt computers and extra ecu's in these cars there is not a whole lot of room under the panel the stock one is under and I am not sure if it is really safe to put under it or not. Let me know where you all have your computers mounted so I can have a good Idea where to put mine.

 

I've seen some in the glove box or mounted to the side of the trans tunnel. Does the toyota ecu not fit under the panel?

 

I am not sure if it fits under the panel or not I will find out later today I hope it will it will make it a lot easier if not I will try the trans tunnel or on the back of the fire wall and see hoe that works.

 

Does the hood fit?

 

Yes and No it will fit when I am done cutting it the engine is going to stick through the hood some.

 

I got some more work done today and some pics. I know how much you all love JDM **** but this is real straight out of south east asia. I got a set of roadster door sills and roadster speaker covers that will work great when I get my new abs door panels in and get rid of the little coner speaker covers. I also got the harness mounted to the fire wall and into the passenger compartment. I also started to mount the ecu witch will be at home right next to the stock 1.6L ecu under the floor panel. Here are some pics to keep all of you guys happy. I mean only good threads have pics right?







This pic is rotated 90 deg. so you have to turn your head to the right to see it other wise it looks like something crazy.

 

What are you keeping the stock ecu for?

 

The stock ECU is running all the body stuff the like the lights heater controls and also the gauge cluster, some of the gauge cluster is controlled by the toyota ecu it is just tapped into the miata harness.

 

Stock ECU doesn't control any of the things you just mentioned. Certainly not lights and heater. AC though I think.

 

The only function the miata ecu controlled that you need to worry about was turning on the fuel pump. By jumping the Toyota fuel pump wire to that yellow connector you removed the only reason to have the miata ecu.

There may be a couple of wires you might want to move to the toyota ecu if it has provisions for them. The clutch/neutral switch and the parking lights. The parking light wire lets the ecu know the lights are on but has no effect on whether they turn on, it just bumps the idle up a bit.

Regarding the AC, it only cut the power to AC under full throttle. It doesn't actually control the AC.

 

I didn't know that so I can remove the miata ecu and all the body functions will still work and I can use the miata harness to send all my signals to the gauge cluster from the toyota ecu. In other words the only thing the miata ecu controls is the engine.

Does the miata ecu control the starter signal?

It doesn't really matter I guess I can run my own relay to send signal to the starter solenoid

 

Yeah as a matter of fact I had my the compute out yesterday as I was installing my MS, eveyhing electrical worked

 

Does the stock ECU run the starter relay signal if not I will wire in a relay and be done.

 

The miata ecu harness is not connected to the gauges in any way. The gauges read directly from the sensors on the engine. Which gauges do the toyota ecu control?

No.

 

It does not send the signal to the water gauge or the tach?

 

Nope. There are 2 temp sensors on the back of the 1.6L. One goes directly to the gauge and the other to the ecu. The tach gets its signal from the coils.

 

IT CONTROLS NOTHING BUT THE ENGINE. Pull it out, everything will work, including cranking the engine, it just won't fire obviously. Is this weird for a car of this era? Does the Toyota ECU control everything?

 

Yea for the most part the toyota ECU controls everything it gives signal to the tach, the water temp. and almost all the cluster other than the lights and the fuel gauge witch is direct. I will pull the stock 1.6L computer out. Then I guess the tach wire I hooked to the mazda harness for the ignitor won't run the gauge. lol That just made things a whole lot easier. I will have to change my water temp. hook up I made at the ecu other than that all I did was steal power and ground from the miata ecu. I knew I joined this forum for a reason you guys are filled with all sorts of good info. Thanks if I run into more problems I will be sure to let you know.



On another note everything under the dash is wired. Minus the water temp wire I need to re-run now. So all I have to do is figure out what wire I need on the toyota alternator to excite it and run the power wire to that and the starter and I should be able to at least start the engine. I got the fuel pump all hooked up and running, it runs when the key is in the run and start position but not accesory. Thanks agian guys and I should have a video of it running in the next two weeks or so.

 

Ok so I checked all my wiring again and all I had to do was remove the wire I had from the toyota ecu coolant temp sensor that I had hooked up to the Miata ECU temp wire witch I now know is not connected to the gauge at all. I have a jumper wire hooked up from the tach signal on the back of the gauge cluster to the Ignitor wire on the toyota ECU. I am not positive if this will work or not but worst case I will have to extend the wire to the engine compartment. I will let everyone know how it all works when I get the toyota fuse box under the hood and get the starter and alternator hooked up.

 

Which temp wire did you use? The one that goes to the ecu is the green connector at the back of the head. The black connector w/single wire goes to the gauge.