Ignition problems..I'm completly stumped.

[DuctTape]

Go buy a cheap multimeter and check coil resistance to spec, voltage to coil in run to spec.

If that doesn't identify your problem, then I'd say do what I do when I get stumped by a bronco problem: give that hunk of iron a good cussing out, wave your hands in the air, maybe throw a few things around the shop. Then, threaten to sell the beast for scrap. Continue cursing and grumbling under your breath on the way back to the kitchen. Pour a stiff whiskey, grumble some more, and go to bed.

If you face the same problem the next day, repeat above procedure until you figure it out.

Has worked every time for me so far.

 

[Delbert]

check rotor and distributor cap for contact?

Not sure how to check that. There is no sign of the rotor rubbing the contacts, or electronic module and nothing is broken off. It did run perfectly well after I replaced the points/module today. but after I shut it off and went to restart it soon after, it was a no go.

 

[Delbert]

Go buy a cheap multimeter and check coil resistance to spec, voltage to coil in run to spec.

If that doesn't identify your problem, then I'd say do what I do when I get stumped by a bronco problem: give that hunk of iron a good cussing out, wave your hands in the air, maybe throw a few things around the shop. Then, threaten to sell the beast for scrap. Continue cursing and grumbling under your breath on the way back to the kitchen. Pour a stiff whiskey, grumble some more, and go to bed.

If you face the same problem the next day, repeat above procedure until you figure it out.

Has worked every time for me so far.

Thanks for the great advise. Made me laugh too. I will give that a shot or two. It may take three. ;D

 

[DuctTape]

Ok just checked. The coil does send a spark when cranking engine. It's just one spark for each attempt it's not continuous though?

Are you getting spark at the plugs? There is probably a better/safer way to check (induction timing light maybe?) but I was taught just to hold the electrode at end of wire close to block and crank to check spark.

If coil resistance is right and coil voltage in run is right and if no spark at plugs but spark at coil, smells like the points assembly failed.

 

[Viperwolf1]

Try this for a temporary test. Run a good wire from the positive battery terminal or starter solenoid to the positive side of the coil. Then try starting it. If it works, your ignition resistor wire under the dash is done.

 

[Delbert]

Are you getting spark at the plugs? There is probably a better/safer way to check (induction timing light maybe?) but I was taught just to hold the electrode at end of wire close to block and crank to check spark.

If coil resistance is right and coil voltage in run is right and if no spark at plugs but spark at coil, smells like the points assembly failed.

Just checked again to confirm....No spark to the plugs.

 

[Delbert]

Try this for a temporary test. Run a good wire from the positive battery terminal or starter solenoid to the positive side of the coil. Then try starting it. If it works, your ignition resistor wire under the dash is done.

Ok tried it and still no go. Thank you Viperwolf and everyone else. I'm learning a lot, unfortunately I haven't learned enough to be able to figure this out yet.

 

[Wyo4x4er]

your coil should spark more than once. Id say bad coil, but need to figure out why, as the now start is just another symptom.

 

[Delbert]

your coil should spark more than once. Id say bad coil, but need to figure out why, as the now start is just another symptom.

If it is a bad coil and I replace it...are there things that can cause it to go bad or did I possibly get a bad coil off the shelf.

 

[Viperwolf1]

Coils do go bad occasionally. Usually the resistor wire burns up before the coil though. Disconnect the wires on it and measure the resistance between the two screw posts. Then measure resistance from the positive side to the high tension terminal. Should be just a couple ohms between the screws and possibly up to 10K ohms to the high tension terminal.

 

[JAFO]

Look at this website...

http://www.chargerr.com/Ignition/Ignition.htm

Shows wiring and how to check the ohm reading of the coil.

My engine has the Mallory Aftermarket Electronic Ignition a little way down the page. That diagram shows you how the electronic type points are hooked up. Shows the wiring in very simple terms.

You could have something grounding out your circuit some place. That would throw a wrench in the works.

So, divide and conquer. Do as the earlier person suggested. Make the circuit as simple as possible. Remove all the wires from the coil (tag them so you know how to put them back) and then just have the coil - (minus) hooked to the minus from the distributor. The distributor + (plus) hooked to the 12V side of the ballast resistor. The RUN in that drawing is the +12 volts. The START is not needed for the test, but make sure the other side of the resistor is to the + on the coil so the coil gets power when you connect the RUN wire to the positive of the battery.
So when ready to test, clip the +12V to your positive of the battery (this is the RUN wire in the drawing). The thing should spark when you crank if those parts (coil, resistor, distributor) are good. Check the resistance of the ballast resistor. They are usually marked. Such as .8 ohm or 1.6 ohm. The purpose of the ballast resistor is just to limit the current through the coil. If the resistor is open you won't get spark because the coil won't be getting any voltage. For a test you can bypass the resistor. Just clip a jumper wire across it, taking it out the circuit. Just put it back in the circuit for normal operation.

What happens is that when the 'points' are closed, voltage flows through the coil creating a magnetic field. When the points open, the voltage flow is broken, the magnetic field collapses and it flows out the coil primary to the distributor cap as a very high voltage. You can read about the basic principles of an ignition coil here-
https://en.wikipedia.org/wiki/Ignition_coil

So, what needs to happen is the points (or electronic system) has to keep making and breaking the ground to the coil so it can produce the high voltage.

Last thing....did anyone already say this...is the distributor turning? Make sure you note with the cap off that the rotor is turning.

 

[Delbert]

Look at this website...

http://www.chargerr.com/Ignition/Ignition.htm

Shows wiring and how to check the ohm reading of the coil.

My engine has the Mallory Aftermarket Electronic Ignition a little way down the page. That diagram shows you how the electronic type points are hooked up. Shows the wiring in very simple terms.

You could have something grounding out your circuit some place. That would throw a wrench in the works.

So, divide and conquer. Do as the earlier person suggested. Make the circuit as simple as possible. Remove all the wires from the coil (tag them so you know how to put them back) and then just have the coil - (minus) hooked to the minus from the distributor. The distributor + (plus) hooked to the 12V side of the ballast resistor. The RUN in that drawing is the +12 volts. The START is not needed for the test, but make sure the other side of the resistor is to the + on the coil so the coil gets power when you connect the RUN wire to the positive of the battery.
So when ready to test, clip the +12V to your positive of the battery (this is the RUN wire in the drawing). The thing should spark when you crank if those parts (coil, resistor, distributor) are good. Check the resistance of the ballast resistor. They are usually marked. Such as .8 ohm or 1.6 ohm. The purpose of the ballast resistor is just to limit the current through the coil. If the resistor is open you won't get spark because the coil won't be getting any voltage. For a test you can bypass the resistor. Just clip a jumper wire across it, taking it out the circuit. Just put it back in the circuit for normal operation.

What happens is that when the 'points' are closed, voltage flows through the coil creating a magnetic field. When the points open, the voltage flow is broken, the magnetic field collapses and it flows out the coil primary to the distributor cap as a very high voltage. You can read about the basic principles of an ignition coil here-
https://en.wikipedia.org/wiki/Ignition_coil

So, what needs to happen is the points (or electronic system) has to keep making and breaking the voltage to the coil so it can produce the high voltage.

Last thing....did anyone already say this...is the distributor turning? Make sure you note with the cap off that the rotor is turning.

Thank you JAFO. I appreciate the links too. It was recently suggested I bypass the ballast resistor, remove the tach from the coil and run a jumper from the battery to the coil. These three things made no difference. If I understand correctly that is what you are suggesting unless I'm missing something? The diagram of the mallory ignition is exactly how mine is wired. I'm not sure if it's helpful but with the ignition on RUN I stick the probe of the test light into the distributor wire harness red wire it lights up and when I do the same to the green wire I get nothing. In my simple mind that makes me think its the module, it's not picking up. Thanks again for your help I will re read your post and links and try and get a better understanding.

And my distributor is turning.

 

[JAFO]

OK, if yours is the Mallory then make sure that only those components are what are hooked up.

First, ohm the coil to see that it is good. If that checks out (or if you want to try this before even bothering to ohm) simulate points to see if the coil will fire. Do this, disconnect the distributor from the coil, so that you have only 12 volts to the + side of the coil. Now hook a wire to the - minus side of the coil. Use that wire to quickly ground, then remove the minus wire. This will energize and de-energize the coil. Does the coil primary crack fire to ground when you remove the minus wire from ground (having the coil primary plug wire positioned close to some part of the engine so it will spark to ground)? If the coil fires then it is good. So, focus on the distributor.

The coil works like this in the most simplest terms....Power is applied and it builds up an electrical field. When the minus wire breaks (points open) the electrical field collapses. This causes current to flow through the coil windings. Current finds the path of least resistance to ground. This path is out the primary wire at the end of the coil, to the distributor cap, jumps the air gap between the rotor and the terminal leading to the appropriate plug wire, through that wire to the spark plug then jumps the air gap across the spark plug gap. Creates a spark and ignites the gas/air mixture.

 

[Delbert]

I think I found something? With a test light and ignition on run I get 12v at the ignition switch (green/black wire) ....That wire then goes through the fire wall to a connector/harness and then to the ballast resistor. At the harness it also shows 12v but by the time it gets to the ballast it shows only 5V going in and 5v going out. Is that normal? Is it possible I found my problem?

If I run a jumper from the ignition switch to my ballast will that confirm? any harm in attempting that?

 

[JAFO]

You should be reading 12v. I would think there is a dirty connection some place in that harness. Disconnect that and use some electronic contact cleaner spray on the terminals.

If you were to run your own wire from where the 12 volts originates, to where it needs to be supplied you aren't going to hurt anything for a test.

 

[Delbert]

I think I found something? With a test light and ignition on run I get 12v at the ignition switch (green/black wire) ....That wire then goes through the fire wall to a connector/harness and then to the ballast resistor. At the harness it also shows 12v but by the time it gets to the ballast it shows only 5V going in and 5v going out. Is that normal? Is it possible I found my problem?

If I run a jumper from the ignition switch to my ballast will that confirm? any harm in attempting that?

Or did I already rule that out by running a jumper from battery to coil? I will try what you suggested with the coil..... Last night I pulled the coil to distributor wire at the distributor and did get a spark when grounding it.

 

[JAFO]

It is very hard when we can't really see what you are doing. All I can recommend is to make the circuit as simple as you can so you can diagnose. Try to eliminate various things. Verify the coil is good, then move on.
Sounds like you could have a badly corroded wire or a wire that is broken/corroded and acting like a resistor instead of a conductor. Voltage divides through resistors. If you put three resistors in series and then measured the voltage from ground to the junctions where the resistors were joined, you would see different voltages based on the resistance. E over IR. Meaning E = voltage, I = current and R = resistance. E divided by I = resistance. E divided by R = current. I times R = voltage.

 

[Delbert]

It runs...it runs it runs!!!!!

It is very hard when we can't really see what you are doing. All I can recommend is to make the circuit as simple as you can so you can diagnose. Try to eliminate various things. Verify the coil is good, then move on.
Sounds like you could have a badly corroded wire or a wire that is broken/corroded and acting like a resistor instead of a conductor. Voltage divides through resistors. If you put three resistors in series and then measured the voltage from ground to the junctions where the resistors were joined, you would see different voltages based on the resistance. E over IR. Meaning E = voltage, I = current and R = resistance. E divided by I = resistance. E divided by R = current. I times R = voltage.

JAFO You are awesome! Thank you for hanging with me on this. I can't thank you enough. Everyone here has been great. I just ran a jumper from 12v to coil AND IT RAN! Viperwolf1 suggested this last night I must have not made a good contact or something when I jumped it. Looks like I have some wiring to do. Again... thanks a million! ;D

 

[Delbert]

Turned out to be a wiring issue between the ignition and ballast. Thank you JAFO for staying with me and figuring it out You explained a lot and I have a better understanding now because of it. Viperwolf You had it right when you had me run a jumper from the battery to the coil but somehow I missed it. I think DucTape's suggestion of taking a shot, cursing at it and going to bed and looking at it today was valuable. Wyo4x4er, Jw0747, SHX669 and cohammer I can't thank you guys enough. I hope I'm able to help out here someday.

 

[JAFO]

Glad to hear you got it. Way to hang in there.