Spark from coil to dizzy but it stops there?????

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Mac2Night
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Spark from coil to dizzy but it stops there?????

Post by Mac2Night »

First, let me state that i bought a new-to-me '70 F100 4x4 with a built-to-the-hilt 460 in it nearly a month ago. it ran like a beast and has every performance upgrade anyone could want. after owning it for a couple of days, I made the decision to charge the battery as it seemed a little weak. During the process of attaching the charger, I made an idiotic mistake (lets just leave it at that) and from that point forward, the truck would crank but never start.

In my effort to troubleshoot the problem, I found I was not getting any spark from my MSD #6420 ignition box to the coil. Well, I replaced the MSD ignition box with a new digital unit (#6425) and I now have spark from the box to the coil wire going into the distributor, but no spark from any of the plug wires. Thinking it could be an issue with the distributor since I was getting spark to the coil wire, I pulled the distributor and replaced the magnetic pick, rotor and cap up over the weekend with a new ones, but I have not reinstalled it to test it out. The pick up's non-magnetic area was all rusty and the dizzy had contaminants in it that looked like sawdust almost in it. I cleaned everything out (changing the pick up was way more of a pain than I thought and the instructions did not give me any idea that you had to take the whole distributor apart to install it....MSD instructions suck IMO). I can't think of anything it could be that is not sending a spark from the coil into the distributor and to the plug wires.... any thoughts on why this might be happening? I know I will know that once I get the distributor back in I will find out if my work was successful, but I would also like to hear if you guys might think it could be something else keeping the spark from reaching the plugs. My whole system is MSD and worked perfectly until I sent some extra juice to the system whe I dropped the trickle charge's positive clip onto the positive side of the starter solenoid by accident. Okay there, I admitted my mistake...... :(

Any help is greatly appreciated as I need to get this truck running and back on the road soon (been down for three weeks now and frustrating as all get out)!

Mac
Mac2Night
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Re: Spark from coil to dizzy but it stops there?????

Post by Mac2Night »

No one has an opinion on this? I could really use some help thinking it through please.

Thanks,
Mac
Clunker
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Re: Spark from coil to dizzy but it stops there?????

Post by Clunker »

I assume that if you have an MSD system, then you have an electronic ignition. If you have a spark to the distributor cap but nothing beyond that, there are very few things that it could be. Obviously, some of the electronics were damaged, so it might be worth checking for conductivity at every stage, but my first guess would be to look at the magnetic sensor inside the distributor. It is a fairly sensitive instrument and would definitely explain the problem if it got fried.
1970 F250 CS: 360, RV cam, Edelbrock Performer 390 intake, Holley 600, headers, Pertronix II, Flamethrower coil.
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