Toyota Wasted Spark
Moderators: jsmcortina, muythaibxr
Toyota Wasted Spark
OK, well, for coils I bought 2 from a 97 Camry, as the plug wire end fit my spark plug wires, saving me a lot of money versus having custom wires made from Magnecor. Now, my issue is that I thought I was buying two wasted spark coils. However, it looks like I bought 2 wasted spark coil/igniter units. That is, there are 4 wires at the plug and some electronics sealed in the bottom. I can figger out what has to be there: +12v, ground, signal, IGF. But, which are which? Anywone have a schematic for these type of coil units? Any hints on wiring this up with my MS1V3 and MSnS setup? Thanks.
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sparkandfuel.com
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toydoctor72
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I use the coil on plug version of these coil packs. They work real well with
megasquirt since they have a built in ignitor. I use pn2222a npn transistors amplifying the spark outputs on the proccessor. The outputs of the transistors have a 1k ohm pull-up to +5v, and they are connected directly to IGT on the coils. Make sure spark inverted is set to "no". IGF is not used (ignition confirmation to factory ecu). Run a power and ground to the remaining pins and you are done.
If you don't have a schematic yet for these coils, I plan to pin out the coils today.
megasquirt since they have a built in ignitor. I use pn2222a npn transistors amplifying the spark outputs on the proccessor. The outputs of the transistors have a 1k ohm pull-up to +5v, and they are connected directly to IGT on the coils. Make sure spark inverted is set to "no". IGF is not used (ignition confirmation to factory ecu). Run a power and ground to the remaining pins and you are done.
If you don't have a schematic yet for these coils, I plan to pin out the coils today.
Thanks, guys.
muythaibxr found me a schematic of the Camry ignition:
and IGF != IGT. As toydoctor72 says, IGF is the "Fired" signal, or actually, the "I charged a coil" signal back to the Toyota ECU. If the ECU doesn't get a pulsed IGF, it turns off the injectors, I think. Fought that wiring up my factory 20v ECU about 6-7 years ago.
I have the VB921's, and Gary did such a nice job on building this thing that I want to leave it alone. I _think_ that if I put a resistor from pin 2 of the coil/igniter (IGT) to +12v (pin 1), and pin 2 to the output of the VB921, it should work. The igniter shouldn't really care if it is switched 5 or 12v, as long as it is over the threshold and the current is limited by a big resistor. I have a set of CoP's to experiment with, actually. If it does need 5 and not 12, I think a string of diodes or a Zener should do it.
muythaibxr found me a schematic of the Camry ignition:
and IGF != IGT. As toydoctor72 says, IGF is the "Fired" signal, or actually, the "I charged a coil" signal back to the Toyota ECU. If the ECU doesn't get a pulsed IGF, it turns off the injectors, I think. Fought that wiring up my factory 20v ECU about 6-7 years ago.
I have the VB921's, and Gary did such a nice job on building this thing that I want to leave it alone. I _think_ that if I put a resistor from pin 2 of the coil/igniter (IGT) to +12v (pin 1), and pin 2 to the output of the VB921, it should work. The igniter shouldn't really care if it is switched 5 or 12v, as long as it is over the threshold and the current is limited by a big resistor. I have a set of CoP's to experiment with, actually. If it does need 5 and not 12, I think a string of diodes or a Zener should do it.
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muythaibxr
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like I said before, you're going to need a pullup resistor, which is fine, but if these things are anything like my rx7 ignitors (they probably are, both are denso), then the stock ECU is providing a +5v square wave....
So instead of doing a pullup to +12v, you can do a pullup to +5v.
The ignitor itself shouldn't draw much current...
So instead of doing a pullup to +12v, you can do a pullup to +5v.
The ignitor itself shouldn't draw much current...
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muythaibxr
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I hope you're not just leaving it ungrounded... in this configuration you'll want to have it grounded all the time until you're ready to dwell the coil, then you'll want to unground it briefly and then ground it again.
Essentially what you're doing when you ground junction point 1 is pulling the +12v away from the ignitor. So basically you'll want the MS to turn off/on the vb921 if that's what you're using to either pull the 12v to ground or let the 12v go to the ignitor. It's essentially the same thing you'd have done if you used the LED's with pullup resistors, only you're doing it with +12v instead of +5v.
If you just leave +12v or +5v going to the ignitor, most likely it'll eventually enter a current-limit mode, and then fire when you pull the +12v/+5v to ground and away from the ignitor. This could be a problem though if you're testing it by hand because like I said, whenever you're not grounding that junction, you're charging the coil, which could overheat or damage the ignitor/coil unless the ignitor has some kind of built-in current limit or protection circuitry.
To drive this with the MS, you'll want spark output set to "non-inverted"
Essentially what you're doing when you ground junction point 1 is pulling the +12v away from the ignitor. So basically you'll want the MS to turn off/on the vb921 if that's what you're using to either pull the 12v to ground or let the 12v go to the ignitor. It's essentially the same thing you'd have done if you used the LED's with pullup resistors, only you're doing it with +12v instead of +5v.
If you just leave +12v or +5v going to the ignitor, most likely it'll eventually enter a current-limit mode, and then fire when you pull the +12v/+5v to ground and away from the ignitor. This could be a problem though if you're testing it by hand because like I said, whenever you're not grounding that junction, you're charging the coil, which could overheat or damage the ignitor/coil unless the ignitor has some kind of built-in current limit or protection circuitry.
To drive this with the MS, you'll want spark output set to "non-inverted"
I tried drawing the schematic in ASCII, but these boards don't let you put multiple spaces in or I can't figure out how to do it anyway. With the Zener in there, +5V is on the IGT pin and is grounded when I switch JP1 to ground, where the VB921 will go. +12v (no Zener) didn't work too well for whatever reason. IGT doesn't draw much, but the 330 ohm resistor worked and a 4.7K did not.
I'll set the spark to non-inverted. I also have some accurate (I hope) temp observations on both temp sensors, taken with my digital pyrometer. I have the original CLT from the 20v and I got a IAT from a Camry. They both have almost identical resistance readings/temp.
So, I enter these into Easytherm with the MS hooked and powered up and it writes it out to the MS. Then I run MegaTune and read from the MS and write a file out? The last time I tried it, the Easytherm said it couldn't find a file and choked. I have everything (car1, etc.) in the default directories.
Also, I know this isn't the proper sub-forum, but I have a 640x480 pentop running Win98SE and it runs MegaTune, but _some_ of the menu items don't work on it. Just little things like "File" which can be kinda irritating. You can click on it and it looks like it will pull the menu down, but it doesn't. Other menu items do pull down. Oh well, I'll have to find another laptop/pentop to try it on.
I'll set the spark to non-inverted. I also have some accurate (I hope) temp observations on both temp sensors, taken with my digital pyrometer. I have the original CLT from the 20v and I got a IAT from a Camry. They both have almost identical resistance readings/temp.
So, I enter these into Easytherm with the MS hooked and powered up and it writes it out to the MS. Then I run MegaTune and read from the MS and write a file out? The last time I tried it, the Easytherm said it couldn't find a file and choked. I have everything (car1, etc.) in the default directories.
Also, I know this isn't the proper sub-forum, but I have a 640x480 pentop running Win98SE and it runs MegaTune, but _some_ of the menu items don't work on it. Just little things like "File" which can be kinda irritating. You can click on it and it looks like it will pull the menu down, but it doesn't. Other menu items do pull down. Oh well, I'll have to find another laptop/pentop to try it on.
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muythaibxr
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OK, the 4.7K resistor was what I was doing on the rx7 ignitors, with the LED's and pullup to +5v instead of pulling up to 12v and sending it through a zener. Bottom line is you're still doing a pullup type setup, which means that when the MS turns that transistor on, you're pulling the +5v away from the ignitor, and when it's not on, you're allowing the +5v to go to the ignitor (assuming I'm picturing the right thing in my head).Dr.Hess wrote:I tried drawing the schematic in ASCII, but these boards don't let you put multiple spaces in or I can't figure out how to do it anyway. With the Zener in there, +5V is on the IGT pin and is grounded when I switch JP1 to ground, where the VB921 will go. +12v (no Zener) didn't work too well for whatever reason. IGT doesn't draw much, but the 330 ohm resistor worked and a 4.7K did not.
OK.I'll set the spark to non-inverted. I also have some accurate (I hope) temp observations on both temp sensors, taken with my digital pyrometer. I have the original CLT from the 20v and I got a IAT from a Camry. They both have almost identical resistance readings/temp.
Hrmm, It sounds like you're just not understanding how to use Easytherm. There is an Easytherm section on this forum, but without seeing the actual error messages I'm not going to be much help there.So, I enter these into Easytherm with the MS hooked and powered up and it writes it out to the MS. Then I run MegaTune and read from the MS and write a file out? The last time I tried it, the Easytherm said it couldn't find a file and choked. I have everything (car1, etc.) in the default directories.
You just need to turn off the goofy menu effects and stuff. The menus will still work even with it on, you just have to drag the mouse down before the menu will show.Also, I know this isn't the proper sub-forum, but I have a 640x480 pentop running Win98SE and it runs MegaTune, but _some_ of the menu items don't work on it. Just little things like "File" which can be kinda irritating. You can click on it and it looks like it will pull the menu down, but it doesn't. Other menu items do pull down. Oh well, I'll have to find another laptop/pentop to try it on.
Ken
OK, I think I got the Easytherm working. It changed the .s19, burned it, I reloaded your "good tune" and fiddled with a few things like the rev limit (I have it at 6K until I get a knock sensor working. Blew a motor once to that and I'm gun shy.)
I turned off the windows animated menus on my pentop from right clicking the desktop, properties, effects, and that fixed the megatune menus.
Yes, I'm still doing a pullup, basically the same as you have except I am using the zener as a source for 5V instead of internal to the MS. The LED in your circuit is effectively not there (short at forward bias, sort of), so it is 330 ohms to +5v, which is what I have duplicated with the 330 ohm resitor and the zener to ground. I'm not sure what the other resistor you have in there across both the LED and the 330 is for. Maybe a bias?
Thanks again, Ken. You are a tremendous help.
I turned off the windows animated menus on my pentop from right clicking the desktop, properties, effects, and that fixed the megatune menus.
Yes, I'm still doing a pullup, basically the same as you have except I am using the zener as a source for 5V instead of internal to the MS. The LED in your circuit is effectively not there (short at forward bias, sort of), so it is 330 ohms to +5v, which is what I have duplicated with the 330 ohm resitor and the zener to ground. I'm not sure what the other resistor you have in there across both the LED and the 330 is for. Maybe a bias?
Thanks again, Ken. You are a tremendous help.