DCZ Posted June 27, 2011 Share Posted June 27, 2011 I've been researching to install MSII, V3.57 circuit board to replace the stock 83 ECCS and am still unclear on one (or more) point(s): Can you use the stock ignitor to trigger the stock coil, simply using the MS pin 36 signal to gate the ignitor on and off? Do you have to install the BIP373 coil driver IC to do this? Everything I have seen shows pin 36 connected directly to the '-' side of the coil and the BIP373 installed. It seems to me that the stock ignitor should do the same thing that the BIP373 does, which (I think) is to sink some amount of current to trigger the coil. The stock ECCS controls spark (again, I think) by sinking some current to ground to gate the ignitor. So it seems that if the MS can sink the proper amount of current, it could control the ignitor. Has anyone tried this? I don't want to be the first to fry my MS in this way! But if it is this easy, why isn't it written up this way? Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted June 27, 2011 Share Posted June 27, 2011 I suspect it just hasn't been tried. Whether it works depends on how much current is needed to trigger the stock ignitor. Quote Link to comment Share on other sites More sharing options...
DCZ Posted June 27, 2011 Author Share Posted June 27, 2011 I suspect it just hasn't been tried. Whether it works depends on how much current is needed to trigger the stock ignitor. Do you know how much current the MS pin 36 can handle? Anyone have specs on the stock ignitor? Sadly, my practical electronic skills are weak. I do know that too much current is one of the quickest ways to "let the smoke out of the box" Quote Link to comment Share on other sites More sharing options...
DCZ Posted June 28, 2011 Author Share Posted June 28, 2011 The data sheet for the BIP373 is Here. Looks like the Base current is 200mA. It also appears from this diagram that the BIP373 is gated by a positive-going pulse. I thought the stock ZXT control unit pulled the corresponding lead on the ignitor to ground, but I'm not sure. Can anyone verify how either system works? The 83ZXT ignitor (power transistor) is p/n 22441-V0800. I haven't been able to find any real technical info on it thus far... Anyone? Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted June 28, 2011 Share Posted June 28, 2011 (edited) When i ran a ms on my car i used the stock coil/ignitor.The yellow wire is what fires it and connects to the ms.You have to play with the dwell settings a bit though.If the transistor is hot you are running too much dwell . Edited June 28, 2011 by randy 77zt Quote Link to comment Share on other sites More sharing options...
DCZ Posted June 28, 2011 Author Share Posted June 28, 2011 Randy - that's great! Do you remember any details? MS version? Dwell values? Do you know if the signal from MS pin 36 is a positive-going pulse or negative-going? You are the first person I've read about that has done it this way so anything you can describe is helpful. It just seems so easy that I thought maybe everyone with a zxt was using the stock ignitor and thought it was too basic even to mention! Are you no longer using MS on this car? Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted June 28, 2011 Share Posted June 28, 2011 Do you know how much current the MS pin 36 can handle? Anyone have specs on the stock ignitor? Sadly, my practical electronic skills are weak. I do know that too much current is one of the quickest ways to "let the smoke out of the box" Pin 36 itself can take up to 5 amps sustained and more peak amps. The standard JS10 to IGN jumper has a 1K resistor in it, limiting current to 5 milliamps. Quote Link to comment Share on other sites More sharing options...
DCZ Posted June 28, 2011 Author Share Posted June 28, 2011 Pin 36 itself can take up to 5 amps sustained and more peak amps. The standard JS10 to IGN jumper has a 1K resistor in it, limiting current to 5 milliamps. I need to spend some quality time with the MS schematics, but if I read you correctly, I'm NOT likely to burn anything in the MS up, since the current sourced/sunk by pin 36 (aka IGN) is limited to 5 milliamps. This may not be enough to turn on the stock ignitor, but the worst that would happen would be that it would not work, or I damage the stock ignitor if I don't adjust the dwell correctly. I am almost convinced to give it a try, and the fact that Randy 77zt ran his that way is confidence inspiring. Good thing I have some more wiring to go so I have some more time to research. Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted June 30, 2011 Share Posted June 30, 2011 I need to spend some quality time with the MS schematics, but if I read you correctly, I'm NOT likely to burn anything in the MS up, since the current sourced/sunk by pin 36 (aka IGN) is limited to 5 milliamps. This may not be enough to turn on the stock ignitor, but the worst that would happen would be that it would not work, or I damage the stock ignitor if I don't adjust the dwell correctly. I am almost convinced to give it a try, and the fact that Randy 77zt ran his that way is confidence inspiring. Good thing I have some more wiring to go so I have some more time to research. You're reading me correctly. Quote Link to comment Share on other sites More sharing options...
randy 77zt Posted July 2, 2011 Share Posted July 2, 2011 The yellow wire at the ignitor is the trigger wire to fire the ignitor/coil assembly.It needs very little current-its just an old power transistor like you would see on old radios.i dont remember transistor terminolgy from electronics in college but i would guess its the leg that you would call the gate of the transistor.i used about 3.5ms dwell on a falling edge i think.drove about 5000 miles with this set up-no problems.The engine was a 1981 zxt that had the crank angle sensor.if you grind every 2 out of 3 teeth on that crank wheel then take 1 more off at a good spot you can make a 30-1 wheel out of old 1981 zxt parts.The good thing about MS is it doesnt care where or what parts are used to make it work as long as the electronics are correct.I fired my ms with a hall effect sensor and 3 magnets in the flywheel that were 60 degres from tdc and 120 degrees apart .I used the 81 zxt dumb distributor .But i am currently running my car with another brand of efi using the 1981 crank wheel modded to 30-1 and a hall effect gear tooth sensor.Somebody probably could make the 1981 cas work with ms.But most people tend to copy other people's work. Quote Link to comment Share on other sites More sharing options...
J240ZTurbo Posted July 18, 2011 Share Posted July 18, 2011 I just intalled a ms2 v3.0 mainboard with the the 280zxt ignater and got no spark please help... Quote Link to comment Share on other sites More sharing options...
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