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Electric Ignition help

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If your wiring checks out, take a spare spark plug, pull off a plug wire and insert the spare. lay it on top of the unpainted aluminum valve cover. When you crank it, you can see if you get a teeny yellow spark at the plug. You might even be able to see if from the drivers seat through the windshield.


Do you see spark? Or no Spark?

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i did that and i didnt see a spark earlier today. i even tried to shock my friend with a extra spark plug by having him hold it as i tried turning over the car but nothing :mad: :D.. the only thing i can think of is maybe i accidently crossed the wires the first time trying to start it and fried the matchbox if thats possible

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and fried the matchbox if thats possible


Ummmmmm...yeah...thats pretty darn possible.:blink:


Bummer...you may have lucked out and it could be something else...but I have seen new boxes get trashed this way...sorta depends on the complexity of the system.


Best to ya man.:cool:

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damn that would suck if i did... the dis. looks brand new.. the only couple things i can think of is that i might of fried the matchbox.. the oil pump drive not being at 11.28 i dont know how to check that.... and mayb when who ever put the dis. in didn't set it at tdc... im not sure if the oil pump drive or not being at tdc would effect having any spark at all or not..

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i think that would only affect when the current passed thru the rotor, i dont think it would cause it to not spark at all. Unless someone just didnt put an oil pump drive in there......

Edited by h2theizzo
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I haven't heard of frying them before. But I did hear the aftermarket (non-Hitachi) modules go bad quite often. I personally have never come across a bad one and have worked on about 20 different ones.


Check the pickup resistance: Key OFF, ohmmeter between the two wires on the matchbox (red & green wires -- NOT the T-connector). It should be about 400 ohms (set VOM to 1000 ohm scale). If "substantially" lower or higher than 400 ohms, the pickup is either bad or a wire is pinched or shorted.

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Yes 12V is plenty.


Inside the coil is just a coil of wire. So the - terminal is connected to the + terminal by a wire. Yes, you'll see 12V on both terminals when the engine is not turning.


The coil + should have same as battery voltage with key ON. The coil - should have same, unless it is firing when it is momentarily connected to ground. But with EI that only occurs when the distributor is turning.


But there is a resistance to the coil, so check that. See the complete list of steps for testing the matchbox system here: Matchbox Testing


Let us know what you find. If you need a replacement matchbox I'll send you a known good one for $20 including shipping. But do all the test Steps first to ensure the wiring is correct and that the pick-up is OK. Don't want to fry another one :-(

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When running the coil - terminal should be close to ground potential with power flowing through the coil to ground at the module. A signal from the pickup momentarily removes the ground, causing the magnetic field of the coil to collapse firing the plug. I don't think you should have a full 12 volts on the - side of the coil, maybe a few volts as it should be grounded by the module. Check that the module is firmly mounted (grounded) to the dizzy and that the dizzy is grounded to the motor.

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I don't think you should have a full 12 volts on the - side of the coil
With a breaker-points system, you definitely will have 12V on both sides when the points are open. When the points are closed, you have ground on the - side.


With the matchbox EI system, when the engine isn't running, is the coil - side normally grounded or ungrounded? Unless we know for sure, then we can't say if it is a problem or not.

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Sure you can do that, and it will run OK.

It's good for testing.


The problems are:

1. when you turn your key to OFF, it will still draw current

2. There is no fuse, so if something goes wrong, the wire melts, in worst case catching on fire


If you are trying to find the cause of the problem, run through the Test Procedure.

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It won't shut off.


With the matchbox EI system, when the engine isn't running, is the coil - side normally grounded or ungrounded? Unless we know for sure, then we can't say if it is a problem or not.


Have to assume it would be at ground with the key on. Once the motor starts to crank the magnetic pickup signals the module to break the connection and the coil fires.


If you have measured 12 at the + side of the coil, a jumper from the battery won't help. Check that the module and dizzy are grounded.

Edited by datzenmike
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Did some research. My '78 FSM for the remote igniter states that primary power to the coil is cut if ignition is ON but motor not running. This is good news as I have often left the key on to listen to the stereo.. no accessory position.


Also there is a limiting circuit to control the current flow below a certain level. This may explain why these modules almost never burn out.


It also says that the EI works exactly like the points. Current flows except when the pick up coil signals it to break the circuit.

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Pull coil wire from cap and ground it

Set Voltmeter to 20V DC scale

connect Voltmeter between distributor case and the "B" connection (stem of T)

Crank engine (key at START) and observe voltage



Voltage more than 1V below Battery cranking voltage from Step 2 (or below 8.6V). Check ignition switch, fuse and wiring


so i followed the list and this is what i have to do. so im glad i didnt roast my match box :) but idk were to start on wiring... i grounded my battery to my block and then have a ground from my valve cover to my strut tower.. are either of those bad grounds and thats y im getting no power to the coil when turning the car over??

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put "points "back in



...idk were to start on wiring...


Hey jonesy,


I just did this on my wagon. I used Pertronix, but the wiring is exactly the same (except the wires go to a pertronix pickup instead of the matchbox you have). I think maybe your making this seem a little harder than it is. There are really only a few things involved in the system.


You said you don't know about the wiring. Just refer to the diagram ggzilla posted. As he said it is very simple. I would start by making sure everything is wired just like his picture:



Wiring at the coil should look something like this:



After you have it wire correctly. check for spark (use procedure above). Make sure you are checking this correctly. If you actually have spark, and don't realize it, you'll waste your time trying to get spark when you need to be moving on to checking timing, or something else.


If you don't have spark, check for 12V at black and white wire (remove wire from coil, and check with test light. Note: key must be on.).


If that is good, it's probably either the matchbox, the pickup, or the coil. Test each one of these (procedures above).


Hope this helps. Just try not to make it too complicated. Divide the problem up. Once you know one thing is good, move on the the next thing to check. I think once you get it fixed, you'll wonder why it seemed like such a pain:D


btw, cool Wagon!!

Edited by 72wagun
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