Weird firing issue.

[raidmagic]

I have a 72 350 in my car. It had a coil/ points set up in it and I couldn't get any spark so I bought a Mallory breakerless dist. and I can get spark when I test it per thier directions and I can get the coil wire to spark against the manifold but it only does it when I am turning the key back to off and if you just click the key off an on it will spark against the mainifold but there is no spark of any kind at the end of a wire with a plug plugged into it.
Any ideas. My wiring is existing but from the looks of it it is wired like the diagram in this thread ( http://www.tbucketeers.com/forum/f10/starter-wiring-2909/ )with the exception of the red wire from the dist. goes to the ballast resistor. That two is per Mallories suggestion.
Thanks for any help.

 

[409T]

Do you have a distributor that will not work without a 6AL box or something similar?

 

[raidmagic]

Do you have a distributor that will not work without a 6AL box or something similar?

Nope. We have one on dad's car with no issues.

 

[TexasT]

Hey Raid Magic, Sounds like your ignition is not wire to the ignition side of your switch. Your ignition switch is set up to when you turn it to start, the only thing that is hot is the ignition and the starter motor so they get full power to crank, if your ignition is wire to the run side of the switch, by the time you let off the starter and the ignition can fire your engine is no longer spinning, so it cant start. try cranking it over and quickly let the key go back to run. If it starts thats your problem.Hope this helps Raid

 

[raidmagic]

Hey Raid Magic, Sounds like your ignition is not wire to the ignition side of your switch. Your ignition switch is set up to when you turn it to start, the only thing that is hot is the ignition and the starter motor so they get full power to crank, if your ignition is wire to the run side of the switch, by the time you let off the starter and the ignition can fire your engine is no longer spinning, so it cant start. try cranking it over and quickly let the key go back to run. If it starts thats your problem.Hope this helps Raid

Maybe for now I'll bypass the key and see what happens. It is wired to be on "Ign" but the switch might be bad. I'll remove it from the circuit and see what happens. Thanks

 

[donsrods]

Diagnosing over the internet is hard, but here is one possibility. The way Chevys are normally wired is that in the "start" position you are only feeding juice to the starter solenoid out of the ignition switch. The current to fire the coil while cranking is supplied at a full 12 volts from the little post that is to the left of the fat terminal on your starter solenoid. Then, once the engine fires and you release the key the "I" or "Ignition" post on the starter takes over and feeds voltage to the coil, generally through a resistor to drop the voltage to 4-7 volts.

It sounds to me like you are starting to spin the engine over, and no current is flowing from that wire from the starter to the coil, but when you release the key you get a momentary burst of juice from the I terminal. There are generally 3 posts on a Chevy starter. The fat one is where the battery cable goes. The skinny one to the right goes to the "S" or "start" post on the ignition switch. And the last skinny one, to the left of the fat post is the one that feeds pure 12 volts to the coil ONLY WHILE CRANKING.

I think that is your problem.


Don

 

[Ted Brown]

Diagnosing over the internet is hard, but here is one possibility. The way Chevys are normally wired is that in the "start" position you are only feeding juice to the starter solenoid out of the ignition switch. The current to fire the coil while cranking is supplied at a full 12 volts from the little post that is to the left of the fat terminal on your starter solenoid. Then, once the engine fires and you release the key the "I" or "Ignition" post on the starter takes over and feeds voltage to the coil, generally through a resistor to drop the voltage to 4-7 volts.

It sounds to me like you are starting to spin the engine over, and no current is flowing from that wire from the starter to the coil, but when you release the key you get a momentary burst of juice from the I terminal. There are generally 3 posts on a Chevy starter. The fat one is where the battery cable goes. The skinny one to the right goes to the "S" or "start" post on the ignition switch. And the last skinny one, to the left of the fat post is the one that feeds pure 12 volts to the coil ONLY WHILE CRANKING.

I think that is your problem.


Don

Don, You are totally right on with this, I also bypass the starting part of the ing. switch and use a good quality starter button, this solves a ton of starting problems...

 

[TexasT]

Sounds like an echo,echo.

 

[raidmagic]

OK so here's where I am after a few minutes playing in the garage. I am getting power to my coil circuit while the key is in the on postion but I'm not seeing 12 volts while cranking. So I am going to hit the parts store tomorrow and buy a starter button and a new ballast resistor and see where that gets me. Thanks for the help guys.

 

[Ted Brown]

Hope that fixes your problem, the ballast resister lowers the running voltage to the points, keeps them from burning up too fast, I hear...

 

[raidmagic]

Hope that fixes your problem, the ballast resister lowers the running voltage to the points, keeps them from burning up too fast, I hear...

How far should the voltage drop? I have 12v on one one side and 4v on the other.

 

[captainjunk]

ballast resistors were for points ignition all the electronic ignitions ive seen have required 12 volts , check the distributors directions it should say voltage requirements in there , at least the pertronix ignitor directions do , hope this helps

 

[donsrods]

OK so here's where I am after a few minutes playing in the garage. I am getting power to my coil circuit while the key is in the on postion but I'm not seeing 12 volts while cranking. So I am going to hit the parts store tomorrow and buy a starter button and a new ballast resistor and see where that gets me. Thanks for the help guys.

I can't stand it.........I'm jumping up and down and yelling at the computer because you are avoiding what is probably your problem. :lol::lol: If you are NOT getting 12 volts to the coil when you are cranking it is because that wire that goes from the skinny post on the starter solenoid is either not there, not hooked up, or bad. Run a wire from the skinny post to the left of the fat one on the starter and run it to the + side of the coil. I bet it starts.

Now I gotta go take a Zanex. :lol::lol:

Don

 

[raidmagic]

I can't stand it.........I'm jumping up and down and yelling at the computer because you are avoiding what is probably your problem. :lol::lol: If you are NOT getting 12 volts to the coil when you are cranking it is because that wire that goes from the skinny post on the starter solenoid is either not there, not hooked up, or bad. Run a wire from the skinny post to the left of the fat one on the starter and run it to the + side of the coil. I bet it starts.

Now I gotta go take a Zanex. :lol::lol:

Don

Yes I am getting power to the coil while starting. I have checked and double checked that. Calm down and breathe.
What I am not getting is 12v because of the ballast resistor. The directions for my dist. say I have to have one so my question is how much power should I see on the other side of the resistor.

 

[raidmagic]

I can't stand it.........I'm jumping up and down and yelling at the computer because you are avoiding what is probably your problem. :lol::lol: If you are NOT getting 12 volts to the coil when you are cranking it is because that wire that goes from the skinny post on the starter solenoid is either not there, not hooked up, or bad. Run a wire from the skinny post to the left of the fat one on the starter and run it to the + side of the coil. I bet it starts.

Now I gotta go take a Zanex. :lol::lol:

Don

I should add that putting a jumper from the starter to the coil does produce spark but it is my understanding that will burn up my dist. Please help me understand. Right now I have it wired up exactly like the diagram provided and linked to eariler in this post.

How was the Zanex?

 

[donsrods]

OK so here's where I am after a few minutes playing in the garage. I am getting power to my coil circuit while the key is in the on postion but I'm not seeing 12 volts while cranking. So I am going to hit the parts store tomorrow and buy a starter button and a new ballast resistor and see where that gets me. Thanks for the help guys.

That's not what you said above..........you said you "are not seeing 12 volts while cranking." Here, I made a little drawing for you. And I am breathing. :lol::lol:

Don

 

[raidmagic]

I posted while you were posting with the result of that. What about the ballast resistor?

 

[donsrods]

Don't worry about it while cranking. You only need the ballast resister for long term running. The few seconds you are cranking you need a hot shot of 12 volts to fire the motor.

Don

 

[HAceT]

Dang Don......what no crayons....:lol::lol::lol:

I want to see colored wires

 

[raidmagic]

Don't worry about it while cranking. You only need the ballast resister for long term running. The few seconds you are cranking you need a hot shot of 12 volts to fire the motor.

Don

Ah ha!! That makes sense now! Thank you so much for clearing it up. I'm going to go try to start it. Report back in a few.