spark at the coil wire,but not the plug wire

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spark at the coil wire,but not the plug wire

Postby 1ruralmailman » Sun Jan 08, 2017 1:55 pm

so i have spark from a new coil going directly to the block,but it will not fire through a plug wire with the plug grounded on the block.what am i missing?i believe since it sparks from the coil wire the points and condenser are working,yes or no?not sure what to look at next.

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Re: spark at the coil wire,but not the plug wire

Postby Eugene » Sun Jan 08, 2017 2:11 pm

Several possibilities, bad plug wires, faulty rotor or distributor cap.
I have an excuse. CRS.

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Re: spark at the coil wire,but not the plug wire

Postby bofahs » Sun Jan 08, 2017 2:20 pm

If the coil wire sparks at the block, you must be doing it by "brushing by" the grounded block to unload the coil. Typically, the high voltage discharges through the coil wire to center of the distributor cap, through the rotor contact and rotor to the poles and plug wires.

So, it sounds like you've got a cap or rotor problem. This is often a corrosion problem, and I'd check that first. Clean the springy contact point on the rotor, lightly scrub the brass contact end of the rotor - then look at the inside of the cap - particularly the inside contacts where the rotor brushes past to dump the voltage to the plug wires.

None of this is, like, "Grunt, grunt, scrub, scrub" a very light dusting with fine sandpaper or Scotchbrite will fix it, if that's the problem. Heck, I've cleaned 'em with a Q-Tip!

Clean the points, of course. "They" say don't use it, but a cheap, paper, emery board has never failed me in this.

Yes, condensors have failed, but, wow, that's a rare failure.

Now, if all of that doesn't fix it, get a tune-up kit that includes a distributor cap, rotor, points cover, points and condensor; get a set of plug wires, and spend a happy 45 minutes putting all of that in.

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Re: spark at the coil wire,but not the plug wire

Postby Bigdog » Sun Jan 08, 2017 9:14 pm

If you're getting spark at the coil secondary the points and condenser are ok. It's either a cap, rotor or timing problem.
If you can't fix it with a hammer, you've got an electrical problem.

My wife says I don't listen to her. - - - - - - - - Or something like that!


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