No spark from coil..

Max Power

Active Member
Jul 31, 2003
1,774
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St Paul
OK, I think it's time for me to take a time out from my car and stare at it for a while.....

I built a nice 393 for it, was out breaking it in, burning tires, etc.

It just cut out on me. I was usung the ignition I had in the car with the last engine, stock dizzy with Pertronix I, stock coil, etc. I upgraded to a Pertronix I coil in the process. It seemed to be running fine, but suddenly cut out. I am getting voltage to the coil, resisted mind you, about 8 volts, and I bought a new stock AND Pertronix coil, a new Ignitor, and I still am not getting spark.

When cranking it over, I will get when spark when starting the cranking, and one when stopping, and none in between.

I'm kinda at a loss right now. Good voltage to the coil, new coil, cap and rotor, new ignitor, etc, and still no spark. I even took a 12v switched souce of voltage and applied it to the coil and nothing.

Any ideas?
 
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Maybe check the ignition switch? Not sure why that would all of a sudden go bad though.

Also check the connectors on each end of your coil wire?

I had a coil wire go bad and my engine was cutting out on me while driving. Replaced the coil wire (like 6Stang7 suggested, mine had high resistance) and haven't had that problem again.
 
I think it might be the ignition switch.

I didn't take an ohms reading at the coil as I have tried the known good old stock coil, two different Pertronix coils, and a new stock coil. Out of 4 coils, I figure one of em was good...LOL.

Even though I seem to have proper voltage to the coil, I may just replace the ignition switch.

Also, new alternator, regulator and battery, as well. Pretty soon I think I'll just buy a whole new car!
 
Save your old parts and put them out on ebay. Someone will buy them and you can recover some of your $ invested into the new parts. You'll have better piece of mind probably with the new parts on your car too.
 
Max Power said:
OK, I think it's time for me to take a time out from my car and stare at it for a while.....

I built a nice 393 for it, was out breaking it in, burning tires, etc.

It just cut out on me. I was usung the ignition I had in the car with the last engine, stock dizzy with Pertronix I, stock coil, etc. I upgraded to a Pertronix I coil in the process. It seemed to be running fine, but suddenly cut out. I am getting voltage to the coil, resisted mind you, about 8 volts, and I bought a new stock AND Pertronix coil, a new Ignitor, and I still am not getting spark.

When cranking it over, I will get when spark when starting the cranking, and one when stopping, and none in between.

I'm kinda at a loss right now. Good voltage to the coil, new coil, cap and rotor, new ignitor, etc, and still no spark. I even took a 12v switched souce of voltage and applied it to the coil and nothing.

Any ideas?

You never said if you have voltage at the coil while cranking.
 
Max Power said:
Yes, I do.

You know, I forgot about the little ground wire inderneath the advance plate. I'm gonna check that when I get home.

ya that's a thought, although I don't think you'd get that initial spark if the dist wasn't grounded.

The rotor is turning ,right? I know, I know, but I had to ask. :D
 
Max Power said:
OK, I think it's time for me to take a time out from my car and stare at it for a while.....

I built a nice 393 for it, was out breaking it in, burning tires, etc.

It just cut out on me. I was usung the ignition I had in the car with the last engine, stock dizzy with Pertronix I, stock coil, etc. I upgraded to a Pertronix I coil in the process. It seemed to be running fine, but suddenly cut out. I am getting voltage to the coil, resisted mind you, about 8 volts, and I bought a new stock AND Pertronix coil, a new Ignitor, and I still am not getting spark.

When cranking it over, I will get when spark when starting the cranking, and one when stopping, and none in between.

I'm kinda at a loss right now. Good voltage to the coil, new coil, cap and rotor, new ignitor, etc, and still no spark. I even took a 12v switched souce of voltage and applied it to the coil and nothing.

Any ideas?

Work backwards replacing everything you replaced with what worked before starting with the coil. So much of our parts are imported crap with little if any quality control, that it must all be checked. I had a coil suddenly die and it turned to be a bad winding. IT would start fine but suddenly quit when the engine got hot -- a sure sign of a broken winding. Since it just cut out on you and didn't sputter, I would guess that something died.
 
Worth, you hit the nail on the head.

The rotor was turning, albeit intermittantly. I finally pulled the dizzy and one tooth on my cam drive gear is broken off and three teeth on the dizzy. Not only was it turning before when I was having problems with it, but it happened to stop at tdc on #1, so everythime I popped the cap when checking initial, it was in the right place.

Expecting, if it was a drive problem, to be the shear pin, when I popped the cap to check it, I merely tried to turn the shaft by hand. You can do that on an engine that is not running and the shaft will spin freely with a broken pin. Of course, it wouldn't move, since it was a gear tooth problem instead of the pin.

OK, now I have a motor with 300 miles on it, and a bad cam and dizzy. How did that happen? That dizzy was the stocker I have been running for years. Maybe the old gear couldn't keep up with the new Melling oil pump.

It's getting damn late in the year to do another cam. :(
 
I did. It will be interesting to see what the oil pump lockup failure is. That puppy was spotless when I put it together.

I have built a lot of motors before, and this is the first time I have has a problem.