No spark. WHY ME!?

[justinburnett]

Alright, for anyone that's been following the hell I've been going through lately you know why I just want to kill myself now.

Just put in a new engine and trans for my 73 truck. I'm currently getting 0 spark. Have the old points type distributor and it worked fine when I pulled it a month or so ago.

Currently to the coil I have a yellow wire from the harness going to positive, plus the condensor thingy, and the wire from the dizzy goes to the negative.

I have no spark at the coil. What could be causing this and how do I fix it ASAP? my brain is so fried right now I can't even think straight, and my wallet is empty. Thanks.

I'll be away from the computer till tomorrow morning. have to go to work. Hopefully tomorrow i can make it work.

P.S. I did check the power lead to the coil and it is hot when the ignition is on. Also I'm getting no spark from the coil, not just to the plugs.
I don't know anything about breaker points whatsoever, but my idea is that they close the negative connection as the dizzy is spinning? Maybe I'm wrong.
basically, the only thing it could be is either the points are no good, or the coil is bad, right? All ideas welcome.

[orbot]

have you tested the coil wire that goes to the dizzy?? if it does not have any spark then replace coil and re check if it does then take thoose points off and use some sanding paper and give them light pass with it cleaning the surfaces that does contact...orrrrrr get HEI my friend.

[Restrorob]

Put your test light or multimeter set on DC volts on the neg post on the coil, As you crank the engine over the test light should flash or meter show a continuous up/down surge of voltage. This will be the points opening and closing, If you get nothing try cleaning the points with a business card and check gap, Rotate the engine so the points are positioned to their widest opening then check/adjusted as needed. IIRC should be 0.20".

If you do have a pulsing test light or meter on the negative coil post while cranking I'd venture to say the coil is faulty......

Good Luck

[justinburnett]

Will do in the morning. Just going to start with a new coil to start. Then I'll check what you said. IF I replace the coil, AND the points are working, then what? Or is that really all that could be wrong?
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Also is the condensor supposed to be connected to the positive or negative side?

[James McClure]

OK, let's run thru how standard IGN works, 1 step at a time. Parts list and what each part does. IGN feed from IGN switch (nichrome resistance wire) cuts voltage down to about 9 volts to lenghten point life. IGN feed from "R" terminal on starter. This feeds 12 volts to coil only during start up for a real hot spark. Both these wires hook to + side of coil. Next is wire going to point set. This is hooked to - side of coil. Next is the point set itself and the condenser. The points are nothing more than an on-off switch and the condenser sucks the voltage right down as the points open to aid in collapsing the field in the coil. The coil fires as the field collapses (points open) and then as the points close again the field in the coil builds to saturation level (magnetic field of coil as high as it can go) and the points open again to deliver another spark out the center of the coil to the distributor via the "tower lead". This all happens REAL fast and has been used since the early 30's, BUT, it's erattic, subject to point rub block and contact wear, which in turn changes dwell angle and in turn timing. This reduces efficiency. In my opinion, change it over to HEI, it's a simple change. Just remember to run a full 12 volt feed from the ign switch to the HEI distributor AND remove the wire from the starter entirely. If you don't remove that wire the starter will stay engaged and you won't be able to turn the engine off until you pull the ign feed wire off the dist cap. (ign feed) jim

[Shyguy]

Originally Posted by James McClure

OK, let's run thru how standard IGN works, 1 step at a time. Parts list and what each part does. IGN feed from IGN switch (nichrome resistance wire) cuts voltage down to about 9 volts to lenghten point life. IGN feed from "R" terminal on starter. This feeds 12 volts to coil only during start up for a real hot spark. Both these wires hook to + side of coil. Next is wire going to point set. This is hooked to - side of coil. Next is the point set itself and the condenser. The points are nothing more than an on-off switch and the condenser sucks the voltage right down as the points open to aid in collapsing the field in the coil. The coil fires as the field collapses (points open) and then as the points close again the field in the coil builds to saturation level (magnetic field of coil as high as it can go) and the points open again to deliver another spark out the center of the coil to the distributor via the "tower lead". This all happens REAL fast and has been used since the early 30's, BUT, it's erattic, subject to point rub block and contact wear, which in turn changes dwell angle and in turn timing. This reduces efficiency. In my opinion, change it over to HEI, it's a simple change. Just remember to run a full 12 volt feed from the ign switch to the HEI distributor AND remove the wire from the starter entirely. If you don't remove that wire the starter will stay engaged and you won't be able to turn the engine off until you pull the ign feed wire off the dist cap. (ign feed) jim

Great write-up! I agree Hei is the way to go.

[justinburnett]

Thank You For the explanation. I would go hei for sure except for the fact that what I have is free and hei would cost a few dollars. Right now I'm not able to purchase a new hei dizzy but will in the future. Thanks again. It's almost light out so I'll get on it.
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[justinburnett]

CLeaned out the points and it is sparking just fine. Started backfiring through the carb. Checked tdc on compression stroke. Pulled dizzy and re-aligned #1wire. Still firing through carb and nothing else. Any ideas? When I put in the timing gears I set them at 0 with #1 in tdc position. Is this right? If for some reason I was being dislexic and set it at #2piston instead would that do it? How would I check? Anything else that it could be off the top of anyone's head? Could someone verify the firing order for me? Thanks.
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[xrcr]

SB firing order 18436572.Can't comment with 100% confidence on anything else. Would guess setting timing gears to # 2 would be a problem.
xrcr

[sumran]

Are you sure the camshaft and crankshaft are properly aligned? If you are changing timing chain and gears that is the first step. Then determine TDC on #1 and verify the firing order is correct.

If you are backfiring through the carb you definately have a timing issue.

[justinburnett]

wrong order. Apparently I'm stupid. Was going 18346752 cause I'm a jackass. Instead of looking it up i just thought I'd be cool and know. It's not on my intake cause it's aftermarket.

Still need to dial some stuff in, it's runnin' pretty rough, but she's going! Haven't heard her fire in over a month and after working for days to get this stuff all finished it was so satisfying!

Have good oil pressure, and it's not overheating, so i think I'm doing good. Now to make sure the new transmission works.

Going to run it down to a shop real quick and have a guy give it a once-over and make sure I didn't do anything else goofy that he can see right off.

Thanks!