My 87 toyota supra hardware build

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QFP80 - Contributor
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Re: My 87 toyota supra hardware build

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I managed to spend a bit messing with it today with a friend to help before sundown. Disconnected the CSI, tried 0 and 180 as an offset and couldn't really make out where the light was firing. However, the timing light is only firing maybe once, sometimes not at all. This is happening while the LEDs on the board show ignition events occuring the entire time. I'm going to just assume that the way I have the stock ignitor wired up is not going to work. I'd spend more time messing with it, but its -14 C right now, probably going to get to -20. I think the problem is likely that the multiplexed inputs to the igniter (igda and igdb) need to be set high for far longer than the dwell times. The connector for the new ignitor arrives thursday, so I will probably just wait until then.

However, if you think it would be easy to configure freeems to work with this old igniter, I might try that. Getting the igt output to work should be trivial, just treat it like a distributor with all output events being on the one pin. The other two pins would need to send high or low depending on the current crank angle. Would that be something relatively simple to implement? If so, I might take a swing at it, otherwise I'll just wait until the weekend. I'm not on vacation anymore, so daylight hours are hard to come by.
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Re: My 87 toyota supra hardware build

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What resolution of control do you need? The "tacho" GPIO bit bang code may be able to take care of it for you. You have an event every 30 degrees and on that event you can either turn a pin on, off, toggle, or nothing at all. You can configure up to 4 of these IIRC. Sounds like you need "dizzy + 2 tacho" or something?

On the other hand, waiting until the ignitor arrives is a good move ;-)

Fred.
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Re: My 87 toyota supra hardware build

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That sounds perfect. I'm going to assume that the outputs would need to more or less be on for a third of crank cycle.

Earlier I found this image:
Image

Looking at that it seems to me that as long as the igda/idgb outputs were set a good time before the dwell period starts, it should enough. I think doing it on 60 crank degree intervals would make sense.
This also seems to confirm my believe I got the #6 instead of #1 when choosing G1 as my trigger.
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Re: My 87 toyota supra hardware build

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Stop worrying about which G signal you used, please. This is a software offset away, and very likely *neither* of them would have had a zero offset.

Yes, that looks doable. You'd need 120 of on/off cycle. This is trivial to achieve, and I can help you set it up if you like. You will have to define which signal goes when, though. You need to know the voltage/current requirements of the outputs, too.
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Re: My 87 toyota supra hardware build

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I spent some time double checking the ignition wiring and learning how to use the benchtest decoder so I didn't have to rely on cranking it to see what was going on. That way I could use the timing light without having to have an assistant cranking the engine -- finding people willing to stand out in the cold with me for extended periods of time is not easy.

Anyway, I still had very intermittant to no timing light firing, but when I got a good fake idle speed going, the tach showed a consistent 1000 rpms and I could actually hear the plugs firing consistently without having the cranking sound in the way. (the igniter drives the tach) I think my timing light just isn't very good. After wiggling wires and trying different parts of the high tension wires, I managed to get a somewhat consistent timing light blink. I hooked up the battery to another running car and that helped significantly, so I'm just going to assume that the low battery voltage was severely hampering the timing light's ability.

While I had that hooked up, I managed to get a friend to crank it for a few minutes while trying to find the timing mark, but still didn't have much success. With about a pulse/second, and not much of a viewpoint of the timing plate, its not very easy. I need to be able to dedicate a good 30-60 minutes with someone willing to crank it for me. I think I might have someone who can help me tomorrow, so hopefully then I'll be able to get the timing figured out.
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Re: My 87 toyota supra hardware build

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Be careful to let the starter cool between cranks. I know the weather is cold, but it takes a bit of time to dissipate from within the windings. Don't burn out your starter getting this happening, if you can help it. The hotel claimed one starter so far, and may claim one more before it's done, too. Good progress research wise, you may not be making practical progress, but the progress you are making feels good to me. Elimination style. I like it.
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Re: My 87 toyota supra hardware build

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Today I made practical progress thanks to a buddy helping me mess with it for an hour. It took a while and some patience, but I figured out the angle to make the spark fire at 10* btdc (being what freeems was, at the time, set to advance to). Assuming I did this by setting the value in 0xC003 to 105 degrees (105 * 50), does that mean I should hardcode that as the decoderoffset in my config?

Also, I know you've explained this but this is one of the things I struggle with for engines... If that angle makes the timing light for #1/#6 fire in the correct position, and knowing that it is wasted spark, is it still possible for me to be 180* off? Or does this fact mean that I am safe to wire up fuel injectors and start trying to start? If you want to look at logs during this I can post, but I see no difference in sensor fluctuations either with or without spark firing, so I don't think noise is an issue.
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Re: My 87 toyota supra hardware build

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Yes! :-)

No, not possible. Provided that your other two outputs are timed correctly for the cylinders you connected them to, you're good. What you can do is mark your 120 and 240 on your pulley and check those too. But if you're confident in your setup and wiring, add fuel and make me proud :-)
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Re: My 87 toyota supra hardware build

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Okay, time permitting I'll be hooking that up tomorrow and hopefully test firing it.

One more thing I just want to make sure of first. I have PT3-5 wired to injector batches 1-4, 2-6, 3-5. PT0-2 wired to 1-6, 2-5, 3-4. With my config, that means injectors 1/4 are set to the same angle as sparks for 1/6, and so forth. {0, 1, 2, 0, 1, 2, 3, 4, 5, 3, 4,5} Is this correct? I don't really fully understand whats going on with the event config, but is the code intelligently putting the fuel injection batches before the spark? I can't really work out in my head how this would look on a timescale. First cylinder that fires is 1, did it get that fuel from the 1-4 injection that occured at that same angle-event, or from the previous one three events prior?
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Re: My 87 toyota supra hardware build

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Ummm, either your post or your wiring is wrong pt0 and pt1 are inputs. pt234567 are outputs with indices 012345 in the config. As long as your cylinder gets 2 shots per 720 it'll be fine. Some fuel will be 360 fresher than the rest. Early fuel evaporates, late fuel is still a mist. etc.
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