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No spark. (UPDATE: figured it out)

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ObscureMachine

ObscureMachine

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3G from RJM hasn't arrived yet, so I tweaked my wiring graphic. Let me know if you notice anything wrong.

PS - I didn't include the other 2 wires on the 3G (I'm getting Ryan's harness)
 

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ObscureMachine

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Got the 3G in. Wired according to pic above.

Turns over.
Has fuel (I can smell it)
But won't fire.

Key on: 904 is hot. 16 is hot. Breaker has power. 60A Fuse has power. Coil + has power.

I'm thinking it may be the new coil wire that I butchered trying to make.

Anyone see anything I'm missing
 
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ObscureMachine

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That seems like an excellent place to start. You should be able to check your coil wire butcher job with an ohmmeter or continuity tester.

Thanks Steve. Was planning on using the ohmmeter tomorrow. If that doesn't work I may use a shotgun.

Should have mentioned, NEW PARTS:
New Battery, Ground, Starter and Alternator wires
New 150Amp Circuit breaker
New 3G alternator
New MSD Coil
New Coil to Dist. wire.

The thing was running the other day. Alternator wasn't charging and battery died, so new alternator and new wires.
 
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DirtDonk

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What kind of ignition system are you running?

And by "alternator wasn't charging the other day", you are speaking of your previous alternator still? Or did you have to replace your most recent one?

Paul
 
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ObscureMachine

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What kind of ignition system are you running?

And by "alternator wasn't charging the other day", you are speaking of your previous alternator still? Or did you have to replace your most recent one?

Paul

I'm just using the MSD Blaster 2 coil. Dizzy has pertronix ignitor 2. Yes, old alternator wasn't charging. Put the new 3G in and it's not firing. Checked all the wiring previously mentioned. Now it's pouring outside so I can't work on it.

Whatcha thinkin' DD?
 
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ObscureMachine

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Put my ohm meter on the coil wire and the wire is good. So, as best as I can tell the problem could be

Coil not working (no fire to dizzy)
Dizzy Cap needing to be replaced

Or........?????? As soon as it stops raining I'll put the timing light on it and see what's happening.

Dumb question, can you put the timing light on the coil wire?

-jim
 

70_Steve

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Dumb question, can you put the timing light on the coil wire?
Not a dumb question at all. Yes you can, and you can/should expect to see the light flash 8 times faster than normal. So, if the engine is running you might not notice a difference. But, if you have the key ON and are using a remote starter button to just turn the engine over, you will notice a difference in how fast the light flashes.
 

DirtDonk

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...Whatcha thinkin' DD?

Oh you know me so well...

Actually, about the alternator events I was just curious if you'd gone through just one, or two alternators.
Regarding the ignition though, I was digging for clues in your, apparently, no-spark puzzle.
I'd not looked at your second diagram, so hadn't noticed the Pertronix install. But now that gives me more ideas.

First off though, what do you have the Brown wire (#) hooked to? If that's the ignition switch, it's not supposed to be there. It goes straight to the coil's positive wire in a ballast-equipped system.
If you're not running a ballast resistor, you don't need it anyway.
So, at least for this diagnosis, unplug it from the starter relay.

And just so I'm clear, what are the two unlabelled boxes on the right side of your diagram? I thought one was fuse box, and one was ignition switch. But they both look like they might be ignition switch related.
Just wondering.

For testing, if you see a spark event through your timing light, you might just be too far out of time to get it to fire.
If you don't see any light though, try these steps to test the coil.

1. Disconnect the Black distributor wire from the negative side of the coil, and also disconnect the main high-voltage spark wire from the distributor. But leave it connected to the coil.

2. Lay it on the engine or body somewhere near a metal surface, but as far away from the distributor body as possible. If your coil is mounted to a fender, this should be easy. If it's right next to it on the engine though, you might need a longer wire. If needed then, temporarily substitute one of the longer plug wires so you can get it farther away from the dizzy.
More on that in a bit.

3. Since you have power to the positive side of the coil already, turn the key on and, with a small jumper wire, momentarily ground the negative side of the coil. You can use any convenient ground, so the longer the jumper wire, the more choices of good ground you have.

Each time you ground and release the wire, you should get a big fat nasty spark from the business end of the coil wire. If so, your coil is good.
If not, either your coil is bad, or something is wrong with the current supply on the positive side.

The reason you keep any stray sparks away from the distributor, is that ignition control modules like the Ignitors, or GM HEI modules, are much more sensitive to voltage spikes near the distributor than a remotely mounted one would be.
The Ignitor and others like it, just happen to be in the very area where you might test for spark using the old "pull the plug wire and look for fireworks" method puts high-voltage sparks. Hence the longer wire for a greater distance for testing.

Good luck. Let us know what you find. The heck with the rain. Just get out there and play with electricity!

Paul
 
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Oh you know me so well...

First off though, what do you have the Brown wire (#) hooked to? If that's the ignition switch, it's not supposed to be there. It goes straight to the coil's positive wire in a ballast-equipped system.
If you're not running a ballast resistor, you don't need it anyway.
So, at least for this diagnosis, unplug it from the starter relay.

Yep the brown wire (262) was connected to the starter relay (solenoid) as it was in the bronco wiring diagram I have. No ballast resister. So I don't need it? or don't need it for the troubleshoot?

And just so I'm clear, what are the two unlabelled boxes on the right side of your diagram? I thought one was fuse box, and one was ignition switch. But they both look like they might be ignition switch related.
Just wondering.

Those are just the wiring harnesses coming out of the firewall. Just my way of remembering which is which and where wires are coming from.

Thanks Paul. I'll try those tomorrow. I've been zapped enough, I think I'll stay inside, watch a movie and have a beer!
 
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For testing, if you see a spark event through your timing light, you might just be too far out of time to get it to fire.
If you don't see any light though, try these steps to test the coil.

1. Disconnect the Black distributor wire from the negative side of the coil, and also disconnect the main high-voltage spark wire from the distributor. But leave it connected to the coil.

2. Lay it on the engine or body somewhere near a metal surface, but as far away from the distributor body as possible. If your coil is mounted to a fender, this should be easy. If it's right next to it on the engine though, you might need a longer wire. If needed then, temporarily substitute one of the longer plug wires so you can get it farther away from the dizzy.
More on that in a bit.

3. Since you have power to the positive side of the coil already, turn the key on and, with a small jumper wire, momentarily ground the negative side of the coil. You can use any convenient ground, so the longer the jumper wire, the more choices of good ground you have.

Each time you ground and release the wire, you should get a big fat nasty spark from the business end of the coil wire. If so, your coil is good.
If not, either your coil is bad, or something is wrong with the current supply on the positive side.

Okay, I did all this. I got no major spark from the coil wire (touching the frame).

However, a got a tiny spark at the end of the wire I was using to ground (the one connected to the - side of the coil). What would that mean?

Timing light does nothing attached to either the coil wire or a spark plug wire.

I do have power at the + side of the coil. I'm thinking what all it could be:

1. Bad coil? But it's a new coil and it was running last week.
2. Bad coil wire? Checked it with ohm meter and it has good continuity.
3. Would the pertronix ignitor (II) have something to do with it since both wires go to the coil?

Arrggggg. I'm kinda lost.

Need more wisdom.

-jim
 
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Put the old coil back in. It worked fine when I pulled it, just thought upgrading might give hotter spark.

Did the same thing. No fire. No light through the timing light.

LOSING. MY. MIND.
 

70_Steve

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Do a resistance check on the coil. I would bet either/both coils are OK, but.. just in case. Now, with voltage on the + side of the coil, one end of the coil wire in the coil and the other end of the coil wire near ground (engine block) take a jumper wire and ground the - side of the coil. Then when you lift the wire there should be a spark from the coil wire. So you should be able to repeatedly ground the - side of the coil and lift the wire, and create a spark.

If you can do that, I would suspect your Pertronix.
 
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Do a resistance check on the coil. I would bet either/both coils are OK, but.. just in case. Now, with voltage on the + side of the coil, one end of the coil wire in the coil and the other end of the coil wire near ground (engine block) take a jumper wire and ground the - side of the coil. Then when you lift the wire there should be a spark from the coil wire. So you should be able to repeatedly ground the - side of the coil and lift the wire, and create a spark.

If you can do that, I would suspect your Pertronix.

Isn't this what I did in post #53?
 
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When I do this (in post 56 and in 52/53) - I get a spark not from the coil wire, but from the jumper wire I'm touching to ground (the other end on the - side of the coil). It does the same thing with both coils

What does that mean? Ignitor problem?

Is there any reason the new 3G would be affecting this? I mean, I don't know how it would, but I may be missing something.
 

70_Steve

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Getting that little tiny spark when you touch a grounded wire to the - side of the coil only means that the primary side of the coil has continuity, and a little resistance. You would get a bigger spark if you touched the + side of the coil. And probably a bigger spark yet if you touched the + side of the battery.

The high voltage spark for the spark plug is created by the collapsing electromagnetic field inside the coil. The coil is nothing more than a transformer, with the primary winding connected between the + and - terminals on the coil, and the secondary winding connected between the coil wire terminal and the case of the coil (ground).

By the way, your coil is grounded, isn't it?

When current flows through the coil an electromagnetic field is created by the primary winding. The lines of flux pass through the secondary winding, but building the field is relatively slow, so no perceptable voltage is created. But when the current flow stops, the electromagnetic field collapses, at many, many more times the rate at which it was created. And those collapsing lines of flux, passing through the secondary winding induce a voltage in that winding. Just like a generator, but instead of moving the conductor through the electromagnetic field, this causes the field to move through a conductor. Anyway, the collapsing megnetic field produces the 20-50K volt spark to fire the spark plug

With mechanical points in the distributor, it's the points connecting, then disconnecting the - side of the coil to ground that builds then collapses that electromagnetic field. You should be able to reproduce that by connecting and disconnecting a grounded wire on the - side of the coil. You should see a high voltage spark from the coil wire to ground.

The pertronics, a Duraspark system, or any other electronic ignition system, including EFI, does this same thing. That is, connecting and disconnecting the - side of the coil to ground, which produces the spark. The only difference is that the switching is done with a solid state electronic device, not the mechanical points.

I read through those posts and didn't catch that you were specifically looking for a spark at the end of the coil wire when you were touching the ground wire to the - side of the coil. Maybe I just missed it...
 
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By the way, your coil is grounded, isn't it?

It is only grounded (negative side of coil) by being connected to the negative wire of the pertronix ignitor? Does it need it's own ground?

I read through those posts and didn't catch that you were specifically looking for a spark at the end of the coil wire when you were touching the ground wire to the - side of the coil. Maybe I just missed it...

I was watching. As I understood the instructions, the spark from the coil wire to ground would be very noticeable. I didn't notice anything.

I know it's probably something obvious. I've retraced the wires numerous times to make sure they're all correct. Should I pull the ignitor and put the old points and condensor back in and see what happens? If I do that, do I need to put in a ballast resistor?

Thanks for the help Steve!
 

DirtDonk

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The only other variable I can see right off hand is, as you say, the Ignitor. If it's shorted to ground inside the distributor, it would stop the coil from firing during the test.
So to eliminate that from the equation, remove the Red wire from the positive side of the coil and do the test again.

Yes, the Brown wire off for the testing. You can then hook it back up once you find the issue, or leave it off since you don't need it except with an ignition system equipped with a ballast resistor. As yours no longer has.

And speaking of which, what coil do you have again? Do you know whether it's supposed to have a resistor or not? No matter what the coil is you use, the Ignitor has to have 12 volts, but the coil might still need a resistor in line to reduce voltage. Depends on the coil.
If you're running the original coil, you need to install a ballast resistor in the positive side, but make sure the Ignitor gets full voltage. In other words, don't hook the Red ignitor wire to the positive side of the coil when a resistor is installed.
Their instructions are probably still not clear on that, but you only hook the Ignitor's Red wire to the coil when it's got the full 12 volts.

And speaking of Ignitors, double-check your gap and ground inside the distributor. Even if the Ignitor module is still good, if you don't have those two things properly set up, you won't get a reliable spark.
Your problem sounds like something different, since you could not get a spark from the coil with the previous test, but it's worth a mention anyway.

And no, in theory, the alternator could not have any effect on the ignition.
Three of the most common problem areas on our old rigs are:
No charge, no spark, no crank.
None of them should effect the other, assuming no shorted circuits between them.
A bad charging system won't keep the starter from cranking or the ignition from firing (until the battery goes dead of course!). Although, a bad starter relay can sometimes (rarely in my experience) cause a no-fire in the ignition system through that Brown wire being shorted to ground. Hence the suggestion to disconnect it.

And if you have any radio noise supressor capacitors hooked up, disconnect them too. Broncos would have had one attached to the positive side of the coil from the factory, so if you left it there with the new system, disconnect it while you're testing.
Even a slight short through it's case could keep the sparks from flying.

Paul
 
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