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MSD ignition problem, need help.


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So I have a Pertronix magnetic pickup, and put in an MSD 6 off road ignition. Have the coil + attached to orange, the coil - attached to black.

The magnetic pickup connector violet is attached to + from the Pertronix unit, and the green is attached to -.

Red wire has switched 12 volts.

White wire is not used.

Big leads are attached to battery.


Did the test per MSD, and I can't get a half inch spark. I can get a 1/8 spark.

12 volt wire is getting power. It's a mechanical fuel pump with dual SUs so it shouldn't need a tach adapter dingus.


The only wire I don't have connected is the tachometer wire, which shouldn't make any difference.


Need to drive to work tomorrow, so I'm either reconnecting it as I previously had it, with just the pertronix, or ??????????

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HA HA!!!! I LOVE PERTRONIX!!! Since I hadn't had any luck, I started browsing the net for info, and Pertronix's website has information and schematics on how to hook up an MSD 6 box using their ignitor, and indeed the wiring is different.




And even though the pertronix uses a magnet, it must not be a magnetic pickup. I was thinking about that when going over the last vehicle I had an MSD on, which was another 78 620 with the matchbox distributor. I'm not sure why it differs, but seeing as the magnetic pickup matchbox has an ignition module, and the pertronix is really just acting as a set of points while using a magnet to trigger, not the actual points, then that's probably the difference. Constantly learning I say.

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The Pertornix still wants a stock point coil and the stock Ballast resisitor in the circut. If remove and 12volts goes to the coil it will over heat the coil and or possible damage the Pertronix Hall cell. Now if you got the 3ohm Pertronix coil then you dont need the ballast.

I dont know if you still have the HOT START wire hooked up. Where it gets the 12volts during "START"


go back to ORG set up ,if not spart I gues the Pertronix broke.

If Pertrix works then the MSD Broke.


I never like the MSDs anyways

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From the several magnetic Pertronix I've set up on Datsuns and Toyotas, somehow or another the stock coil does not last. As a matter of fact, it is recommended that an aftermarket hi-po coil is used in conjunction with pertronix. I've also heard mix reviews when people hook up MSD box with pertronix. You may want to call pertronix and asked them for tech . assistance theya re very helpful

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racerx said,

the stock coil does not last. As a matter of fact, it is recommended that an aftermarket hi-po coil is used in conjunction with pertronix.


I dont believe that statment is true

I have hooked up about 4/5 Pertronix and all are still fine.


Pertronix wants under 4amps current so a minumum of 3 ohms(for a 4 cylinder) in the circut is needed or it says in the instruction they can break.


a stock datsun 510/521 set up is 1.6 ohm stock coil and 1.6 ohm ballast resistor.12volts/3.2ohms=3.75amps


I have a SuperCoil(.7ohms) in my car but added the extra ballast from the SuperCoil kit(.85 ohm ) in series with the stock ballast and it works fine.

.7 ohms +.85ohms=1.55 ohms ,almost same as the stock coil. and then add the stock ballast 1.6 ohms


12volt/3.15ohms= 3.80amps

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So I called MSD this morning, and the tech had me do a bunch of tests and granted the coil wire was getting 5.8 ohms of resistance, and that's what he said to replace. But I sat there thinking the Pertronix worked fine with that shitty wire, so no spark is something else.


Drug out a matchbox dist from a later 620 and jerry rigged the baseplate to work with the L16 distributor housing, and boom, fired right up. Runs shitty and too retarded, but at least she runs well enough to get my other truck back from Les Schwabs. Had brake issues I started on but didn't want to finish.


So 40 minutes late to work due to switching out dists. And it does appear that I fried the Pertronix when I hooked it up incorrectly to the MSD. Dammitall. Think I'm going to get another Pertronix unit and reinstall now that I have the correct schematics.


Never had any problems before, but all the Pertronix I used were not in conjunction with MSD boxes.


EDIT: Forget to mention, hooked up to original setup before I did all this, and yeah, no spark.

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For 85 bucks + shipping and handling I get the Pertronix 1741 like I just burned up.


For 70 bucks (work at NAPA, my cost) + 30 core I get the bigger 20B '79 matchbox distributor.


If I'm going to be running the MSD box, which system would you choose? My worry is that whole leaving the switch on for x period of time damaging the Pertronix, whereas I don't think that's a problem with the stock matchbox dizzy.


Of course, then I need to go find a 2.0 timing cover adapter since all I have laying around are L16 and 18 and they're not oriented correctly. Not that a trip to the local PullnSlave couldn't fix that.


The matchbox distributor is a magnetic pickup, not a hall effect, correct?

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you can get the L20b dizzy(Matchbox) from NAPA but youll still need the L20b timming plate and pedastal. You know there are 2 types???????

How good are they? as the Nissan ones are about 300$


Somebody on here had matchbox dizzys for sale and Im sure they were a complete set.


Pertronix is a Hall Cell

The matchbox is a magnectic trigger I guess.



I left the IGNITION ON for a day and my Pertronix still works.


Personally The FJ20 still had a dizzy coil Nissan trigger sytem and that was a bad ass motor and I dont know why people BUY there MSDs So The matchbox should be more than enough for a L motor. MSDs just cause proplems

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Well, since I didn't have any problems with the pertronix and it's probably a good guess I killed it, I went ahead and ordered another one. I'm still wanting to run the MSD for the multiple spark since I run a crapload of advance with the SUs. Think it might help my lower end quite a bit. I had an MSD on my previous 79 620 with the matchbox dizzy and it worked great. Better than the original anyway.


So I'll hook it up correctly this time and as long as it works, I'll buy another for a spare or throw the 20b matchbox dist in the car just in case.


I'm going to go see if I have the timing plate for the matchbox dizzy and the correct pedestal. Could only find the dist yesterday, hence the dremeling of the plate to make it work on the 16 pedestal. :) Fuuuunnn.

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I'm still wanting to run the MSD for the multiple spark since I run a crapload of advance with the SUs. Think it might help my lower end quite a bit. I had an MSD on my previous 79 620 with the matchbox dizzy and it worked great. Better than the original anyway.


once you hit ~3500 rpm's the 'mutli' spark reverts back to a single spark...




i have both and prefer the ease of the matchbox alone.

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I would just hook the Pertronix back up with the point coil & ballast resisitor and see if it works.


Note on the Pertronix MSD drawing i bet that PERTRONIX FLAMETHROWER coil is the 3 ohm one. Did you remove your ballast? and just run the stock POINT coil straight to 12volts?????? Those stock coil run on 6-9volts need a Ballast otherwise ther Pertronix or the Coil insulations on the wire inside Could burn up!!!!!


YOu say you want to increse your bottom end?

I know SUs dont have a acell pump on their carbs. Maybe is that what your trying to resolve?

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I never run the ballast resistors. Have a coil meant to be used without one, just a generic, not anything fancy.


As far as the MSD, I just wanted a bit more, mainly to better burn the fuel mixture due to the overlap of the cam at low rpm. Rather gassy at idle, but it's where it needs to be as far as the mixture screws are concerned.


And since I already hooked up the MSD, I'm just going to use it. Don't think I can return it anyway, bought it off Jegs or Summit, offline, can't remember which.


I already hooked the pertronix back up to the way I had it and nothing. Definitely cooked it, probably because I had it wired as a magnetic pickup instead of the way pertronix has on their site. Anyway, off to work.

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No, I always remove the ballast resistor. As long as you have a coil rated for 4 cylinders (4 amp), not 8, you're fine. I always run the coil for that. Can't remember what, but it's in the Pertronix instructions. Usually I remember at the time of install and then forget. ;)


But no, the Pertronix dying had everything to do with me hooking up the MSD incorrectly. I've run quite a few past Datsuns on Pertronix, always with the same setup, never had a problem.

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Hmm, yet another interesting twist. Got my new Pertronix igniter today, and wired it up according to that link from Pertronix about it working with MSD, and nothing. So then I immediately switched it back to Pertronix only and it works flawlessly.


So guess I'll give MSD a call about it. Or maybe Pertronix. Seems to me it should work with them, unless their website is outdated, but rather hard to believe. I've spent all this time installing the MSD, running wires, etc., I'd like to use the stupid thing. :mad:


And of course when I switched in my 69 L16 dist tonight, I found the base pedestal for the 20b, which means I didn't have to alter the dist plate on the donor matchbox dist if I had pulled my head out of my butt. Good grief charlie brown.

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  • 3 weeks later...

Well after two calls to MSD and a new Pertronix, I took her off the car this morning, filled out the return slip and shipped the MSD back to Summit. I'll eat the freight, but oh well.


Just goes to show, simplicity is best. In lieu of BRAWNDO SPARKAGE! I got Iridium spark plugs which will probably be just fine. Couldn't tell all that much difference, although top end seemed a bit better. Of course the butt dyno probably can't really tell .0000004 hp. :)

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