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Discussion Starter #1
Anyone on here running a stand-alone engine management system with a factory MKIV auto trans?
 

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Call Larry at Sound Performance

They are currently doing such an install on a Supra right now. ;)

630-893-5002
 
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Discussion Starter #4
I have a car...

...I picked up a theft recovery car. Supposedly, it was a running car minus the gauge cluster and leather interior. When I took delivery of the vehicle, I found that the ECM had also been cut out of the car. They cut the plugs as well, so it is not so simple as buying another ECU from the "For Sale" forum. I do, however, have an extra Autronic SMC engine management computer I can use to run the engine. I am perfectly willing to install the computer into the Supra to get it running, but I was warned by a guy at Toyota that the car's automatic transmission needs the stock ECM to run. I haven't verified this, so I don't know what sort of inputs or signals the car's auto transmission needs to run. I do have the factory manual on the way, but it won't be here for a few days. If it's possible to make things work, I'll keep the car. If not, I'll part it out and get it out of my driveway asap. I'd like to keep the car, however.
 

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Re: I have a car...

HyperRex said:
...I picked up a theft recovery car. Supposedly, it was a running car minus the gauge cluster and leather interior. When I took delivery of the vehicle, I found that the ECM had also been cut out of the car. They cut the plugs as well, so it is not so simple as buying another ECU from the "For Sale" forum. I do, however, have an extra Autronic SMC engine management computer I can use to run the engine. I am perfectly willing to install the computer into the Supra to get it running, but I was warned by a guy at Toyota that the car's automatic transmission needs the stock ECM to run. I haven't verified this, so I don't know what sort of inputs or signals the car's auto transmission needs to run. I do have the factory manual on the way, but it won't be here for a few days. If it's possible to make things work, I'll keep the car. If not, I'll part it out and get it out of my driveway asap. I'd like to keep the car, however.
I'm not too sure about this but... I think when you use an auto with a standalone you use the standalone in conjunction with the stock ECU. Basically the stock ECU takes care of things like A/C and the shifting for the auto, and the Standalone takes care of running the engine. Good luck with your project.

-Amir
 
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Discussion Starter #6
That's what i'm afraid of.

I don't have a stock ECU anymore. I don't really know what would be involved in order to replace it, being that I'm missing the plugs. If I could obtain an ECU with plugs, I'd certainly merge the harnesses. I apologize if I seem rather new at this. I've been a RX-7 guy for years. The Supra is the other car I've always wanted.
 

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You will have to control all your accessories, and also you trans with the stock ecu. Sorry:(

You could get around it by swapping in a GM trans of some sort:)

-Ethan
 

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Re: Re: I have a car...

forcefeed said:


I'm not too sure about this but... I think when you use an auto with a standalone you use the standalone in conjunction with the stock ECU. Basically the stock ECU takes care of things like A/C and the shifting for the auto, and the Standalone takes care of running the engine. Good luck with your project.

-Amir

That is correct, the stock ECU shifts the auto tranny, works the a/c, power steering firmness, cruise control......etc
 
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Discussion Starter #9
Ok, so now the next order of business...

Now the next order of business is to ask what is the best way to score the ECU plugs? I have already located a stock ECU. I imagine a new engine harness would be prohibitively expensive. How much do those HKS piggy back harnesses cost? The VPC or FCON harnesses? Wouldn't they have the ECU plugs? I can repair the harness if I have the plugs.
 

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Re: Ok, so now the next order of business...

HyperRex said:
Now the next order of business is to ask what is the best way to score the ECU plugs? I have already located a stock ECU. I imagine a new engine harness would be prohibitively expensive. How much do those HKS piggy back harnesses cost? The VPC or FCON harnesses? Wouldn't they have the ECU plugs? I can repair the harness if I have the plugs.
\

I have an extra harness Wendell. You shoulda gave me a buzz first. It is fields harness. It has a few wires off but can fixed with minor soldering.
 
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Discussion Starter #12
I have a Full Auto engine and trans wireing harness along with a OBD1 Auto ECU for sale. The Harness is in the car not but will shorty be taken out, it;s in perfect condition. E-mail me a [email protected] if you want it.

Chris
 
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B I N G O

Yessssss! Someone up there likes me! I'm in Hawaii so I don't really know how big Autronics is on the mainland, but when I mention I have one, the response I usually get is "what's that?" I currently have an SMC unit controlling the SR20DET in my 240sx, and my roommate Chris is using an SMC in his Eclipse. I have an RX-7 also, but that car is running a Haltech E6K.

Did you do the install yourself? You said you used to run it...did you switch it out for some reason? I have a bunch of questions concerning the Supra. Do you want to air it out here, or would you like it if I sent you an email?
 
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Discussion Starter #15
ECU questions

OK, assuming I obtain a stock ECU to run the power steering and automatic transmission, what are people doing to incorporate the stand-alone systems? If I just snip wires doing to the stock ECU, won't that set off fault codes? Will the stock ECU run differently? I've never tried to install a computer system like this on a car that is this complex.
 

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I was looking through the Supra Repair Manual trying to figure out a way to incorporate a stand alone system w/the stock ECU as this is the route I'll be taking.
It seems as though you have to fool the ECU into believing it is still running the engine. There are a couple of components that the ECU controls that actually send confirmation signals back to the ECU, one of them being the ignition coils. So naturally, if you interupt that you may throw the thing into fail safe mode.

I would think on a stand alone like a Haltech, you would keep all your stock sensors so that the stock ECU would still be reading these. If the Haltech is able to read the stock sensor that's even better as you can tap into the correct wire and take the reading there. If not, just install the correct Haltech sensors somewhere else.

The only thing the stand alone would be controlling is the injectors and the ignition. As long as the engine is tuned correctly the stock ECU shouldn't be reading anything out of the ordinary and shouldn't throw any fault codes at you.

This is what I'm seeing when I was browsing through the repair manual. Of course you guys with the experience know, but am I somewhat close to how you'd install a stand alone to work in conjunction with the stock ECU?
 
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Discussion Starter #17
I was thinking the same thing

I just picked up the Factory Manual, which the parts guy said had "electrical" in it...and of course, it doesn't have wiring diagrams. What I need to know now is, exactly which sensors does the computer need to know is "working" before it throws a fault code...and also, if the Autronic is controlling the fuel and ignition, and the computer does go into fail-safe mode, so what? It might not matter if failsafe mode does not affect the way the car runs. I don't think the power steering would suddenly go out under failsafe mode...or air conditioning. Transmission, maybe...but that seems unlikely as well. I'm sure someone could easily prove me wrong.

As far as tapping into the stock sensor signal, it could work. I've had some problems with that before. I have a 3 rotor RX-7 which I'm still working on getting running nicely (bitch), and we're using two Haltechs, an E6K and an IG5 to run the engine. (The IG5 runs the trailing plugs only, since the firing order of the 20B is so weird) We had some problems with the computers receiving a strong enough signal when we split each single sensor to 2 computers. The problem was solved with some help from Haltech by pulling a couple resistors but...I think running seperate sensors whenever possible might be easier.
 

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Re: I was thinking the same thing

HyperRex said:

As far as tapping into the stock sensor signal, it could work. I've had some problems with that before.
It will not work... you must modify the crank position sensor to three teeth from 12 and make sure you are using the correct Autronics "single tooth" software. (build 15 I think) You must also have a rectifier box on the stock sensor as the ecu wants a digital, not analog signal.

I'd assume you'll be running an aftermarket ignition-- some kind of MSD box in a wastefire set up. Well here comes your problem.. how do you give the stock ECU a correct RPM signal? I was considering making a device to double the signal, but you run into extreme clock timing problems (pluses must be evenly spaced, and for an adjusting RPM, that poses quite a problem).
 
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Discussion Starter #19
ahhh

Yes, I'd likely be using a DIS-4 if anything, in waste spark mode. That's how I run the SR20DET engine right now, with a DIS-2 and some Accel GM-style twin post racing coils. How to get the signal into the ECU...

Ray Hall in Australia has a 2JZ-GTE swapped into his IS200 down there. I'm not sure if it is an automatic or not. Someone I know is checking.

The other option would be to somehow fit our own magnetic pickup. I haven't even looked at the engine yet to see how that would, if anything, be possible. Kind of busy with mid-terms and all that junk hehe.
 

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I make a crank sensor for the 2j's. That way you can leave the factory crank trigger there to give the ECU a RPM signal to shift the tranny correctly.


Lar
SP


I have been through all this before..... I put a Haltech in a car 3-4 years ago and had the factory ECU shift the tranny.
 
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