2jz Miata build thread
03-09-2010, 03:17 PM
#361
On another note. I need to see if someone can give me some information. I have previously talked to Dr. Tweak about re-doing my Toyota harness witch he said he can make into a "Standalone" harness. This means I only have to piggy back a few wires into my Mazda computer for power, ground, key signal and something else. So the Toyota ECU handles the engine and the Mazda ECU handles the body. This is all fine and dandy but I think I can do it myself and save $500. I need some input on what you guys think. I need to know what and ECU in general need to run by itself. I know some of the stuff but could really use some help. Is this as simple as finding the main power, ground, key signal, starter signal, and fuel pump signal and wiring those into my mazda stuff and then letting the Toyota should handle the rest. If there is anyone in Md that would not mind meeting up one day or talking on the phone to go over this if you are good at wiring that would be awesome. I am going to Toyota today to get all the pinouts for the ECU. If there is anyone in general that is willing to take a look that would be awesome. I am a novice at wiring and I would like the help to reassure my self not that I don't think I can do it I would like some experienced help on my side.
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03-09-2010, 11:03 PM
#362
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I took a really good look at it yesterday actually but I am working a little different I have to piggy back my toyota ecu fuel pump signal to the mazda realay and also with a couple other wires. I am thinking now it might have been easier to use the whole toyota harness and patch it into the mazda harness. Do you by chance have a god pinout of the mazda ecu maybe the one you used for your car? Also wanted to add you car is awesome this is another swap I thought about just the 2J came up me for a goo deal so that is what I went with.
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03-10-2010, 02:28 AM
#363
Actually, I used the s2000 harness, then powered the miata systems by pulling power from the ignition switch of the honda system and running it into the ignition switch of the miata. What you need to do is pin out the toyota computer and figure out which wires trigger the fuel pump relay, then run those wires to the relay and that should then energize the fuel pump. Hope this helps.
Thanks for the kudos on my conversion, it has been a lot of fun to build and drive.
Thanks for the kudos on my conversion, it has been a lot of fun to build and drive.
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03-10-2010, 11:22 AM
#364
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Yea that helps I see a lot of wiring diagrams in my near future. What is it called when you have the ability to do something but have absolutely no desire? I hate wiring it is not per say difficult but my big *** under the dash with a soldering iron for hours on end is not fun at all, but I will do it to finish my car.lol
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03-10-2010, 12:39 PM
#365
You are preaching to the choir...been there, done that, it is not fun. One thing I found was time really went by fast when I was sorting through all my wiring and identifying connections to keep and those to cut out. I don't know about your project, but S2000 wiring harness pieces are expensive and can be hard to come by, so I was really focused in order to make no mistakes.
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03-10-2010, 12:56 PM
#366
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Yea I know the feeling I have been doing my studying so I don't mess up any of my harness I found my for a deal on Ebay because someone didn't know what they had its an actual supra harness and I got it for $200 but they are normally almost $400 so I do not want to mess it up. It will take some time but I hope to have it running in the next few weeks. Did you use the Mazda ecu to control the starter and alternator or did you use the mazda stuff only to power the Honda harness.
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03-10-2010, 05:23 PM
#367
I powered the Honda harness first then the Mazda harness off of the Honda harness Let the Toyota harness power the Toyota EMC and the Toyota fuel pump relay, isolate the fuel pump wires, jump them into the Miata harness and you should be good to go. I konow it iss an over simplification but it is really not that hard. I just posted a couple of pics over on my build thread.
Last edited by hingstonwm; 03-10-2010 at 06:16 PM.
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03-11-2010, 01:02 PM
#369
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I think the toyota ecu is powered by the engine compartment fues box witch I will get from a local junk yard and then all I have to do is give it ignition, wire fuel pump relay, all the grounds, and run the other stuff like tach signal, temp, and oil pressure to the mazda dash and I should be good to go. I will cross my fingers and hope for the best.
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03-11-2010, 01:46 PM
#371
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The fuel sending unit will use all the stock miata stuff the only thing that toyota will interfere with the fuel is it will give the relay the on signal. The tack I think I may have to buy a MSD tach driver to convert the signal but we will see.
Dose anyone have an ECU pinout for the miata I have a pdf form of the miata manual but my computer is so slow it locks up everytime I try and open it so I am just looking for the pinout with the lables of what the pins are not a wiring diagram of circuts and all that.
Dose anyone have an ECU pinout for the miata I have a pdf form of the miata manual but my computer is so slow it locks up everytime I try and open it so I am just looking for the pinout with the lables of what the pins are not a wiring diagram of circuts and all that.
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03-11-2010, 07:46 PM
#374
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All the pinouts I have got from everyone have been very helpful I am in need of one more thing. I may be dumb but I cannot find the ingnition switch signal to the ecu. I am not sure if it is in one of the body plugs or not but if anyone know where it is that would be good.
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03-11-2010, 08:01 PM
#375
Thats because there isn't one. The only wire you will need to worry about is the fuel pump. You should be able to connect the Toyota fuel pump wire to the yellow connector under the dash like is done for the megasquirt.
Here is the spreadsheet I used
Here is the spreadsheet I used
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03-11-2010, 08:15 PM
#376
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Thats because there isn't one. The only wire you will need to worry about is the fuel pump. You should be able to connect the Toyota fuel pump wire to the yellow connector under the dash like is done for the megasquirt.
Here is the spreadsheet I used
Here is the spreadsheet I used
For a recap I am going to connect the Toyota ignition signal wire to pin 1B witch is 12V power (with key on) same as keyed ignition switch, and connect my fuel pump signal to the yellow connector under the dash near the ECU that the wire from pin 1C runs to. Let me know if this sounds right.
Also Toyota uses a Fuel Computer and I am not running that so I am going to run a 12V switched power to the yellow connector and it will act as a theft deterrent and fuel pump signal.
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03-11-2010, 08:57 PM
#377
1B is keyed +12V
1C is the circuit opening relay- the spreadsheet is mislabeled. I didn't use it so I didn't worry about it.
That sounds right. The yellow connector I'm referring to is near the steering column. I'm not sure if 1C runs to that connector. If it does I'll feel like an idiot... I just ran a wire to the yellow connector from the ecu fuel pump output.
1C is the circuit opening relay- the spreadsheet is mislabeled. I didn't use it so I didn't worry about it.
That sounds right. The yellow connector I'm referring to is near the steering column. I'm not sure if 1C runs to that connector. If it does I'll feel like an idiot... I just ran a wire to the yellow connector from the ecu fuel pump output.
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03-11-2010, 09:40 PM
#380
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I found it its the yellow connector that goes to the black relay under the dash next to the steering column and the fuel pump relay signal wire is the purple wire in the connector. Thanks for the help I am sure I will need more before this is over.
To sum this little bit up I am going to used 12v keyed power for the ignition signal to the Toyota ECU and a Switch for the fuel pump relay to the yellow connector under the dash.
To sum this little bit up I am going to used 12v keyed power for the ignition signal to the Toyota ECU and a Switch for the fuel pump relay to the yellow connector under the dash.
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