msd and coil problems

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Nov 5, 2004 | 09:58 PM

chrowen

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From: Louisville, KY

msd and coil problems

I have a MSD 6a box, MSD probillet distributor and blaster coil. Sparks flew between the positive and negative terminal on the coil when we were turning it over. The system ran fine before i had to take part of the motor apart. Aside from pulling the distributor out, i removed/disconnected nothing electrical (except battery terminals). so, it should have been just as good as before. now, there is no spark. I figured the spark sent a lot of vloltage back to the MSD box, so i borrowed another 6a box and hooked it up, but there is still no spark at the plugs or from the coil. Do you think the coil shorted itself out? What else may be wrong? Thanks!

Nov 6, 2004 | 04:49 AM

jwtaylor

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are you getting power to the coil?

Nov 6, 2004 | 07:14 AM

chrowen

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From: Louisville, KY

dunno. i imagine the engine needs to be turning over when i check? otherwise the magnetic pickup from the distributor won't tell the msd box to send power to the coil. correct?

Nov 6, 2004 | 08:29 AM

jwtaylor

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Not sure about the msd ignition but my duraspark/Hei setup has power at the + side of the coil when the key is forward/on...when the vehicle isn't running.

Do you have power to the box?

Sounds like you damaged the coil though.

Nov 6, 2004 | 09:53 AM

sailorpsycho

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From: washington!

Outch thats not good, mmm bad connections maybe? You will not see any power at the coil with an MSD unless the engine is running or you are cranking it, and the voltage is a pulsed 525Volts launched out of a capacitor in the MSD box so it would be hard to measure unless you had a good fluke meter like a 97. Hmm its also quite likely your coil is faulty/failed/cooked, or hooked up wrong, it should have the black and orange wires going to it, and the heavy red and black wires are constant power (preferably good and fresh from the battery and fused too), the small red wire is the ignition switched power signal that tells the MSD its time to go on this should not be triggered by the stock ford ballast wire (if your car has one), and the white wire would be for hooking up points or there abouts. If its wired in right then I would suspect the coil. hope this helps ye some

Nov 6, 2004 | 10:17 AM

chrowen

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From: Louisville, KY

thanks. i also read the manual (say it aint so!) and sailor is correct. there will be no power to the (+) coil since it is a capacity discharge system. I am also using the green/purple magnetic pickup - not the white wire - and it is all hooked up correctly. i am getting 11v (i have the anti-runon resistor installed) through the small red wire, so that is good. if the arch at the terminals send 470 volts screaming down the negative wire back to the MSD box, would it cause any damage? Is it internally protected or would it just run down the ground?

Nov 8, 2004 | 09:09 AM

sailorpsycho

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From: washington!

Honestly I do not know if that wire is internally grounded or not, I would assume so, since its the only source of ground for the secondary side of the coil. I would find a better spot to connect the small red wire aside from the stock ford igniton wire, since that has the resistor in it, MSD boxes like to see 12+ volts or they tend to work erratically. I would also get a volt/ohm meter and check the primary side of the coil to see if its open or shorted straight accross the primary terminals. Other than that if all is hooked up and your getting power/ground every where and the dizzy is turning then I am kinda stumped. However I do admit that the whole spark accross the terminals thing is kinda weird, so I am walking in the dark just like you, but I am kinda leaning toward the coily being cooked, your box should be ok.