Ignition Issues

[69C10@16]

I need some help.

Last September when the new carb got put on and we changed the intake gaskets we also put in a new set of points. When the intake got replaced a few months later we checked them just for grins and they had fried up. Right before we did this I had noticed the truck running really horrible, hard to start, upon engine load it sounded almost like it had some odd detonation. THe problem went away after the new intake got put on. I assumed it was because we put in a new set of unipoints and it was firing correctly again. It was running amazingly.

I'm having the exact same trouble AGAIN. Pain in the butt to start, pain to keep running after you do, odd rattle/tap/knock (It's really hard to describe) sound under a load/acceleration.

I'm guessing points again. I took the dist. cap off and the rotor but I couldnt see the contacts so I can't be sure. I went and talked to my local guy, the ONLY one I'd ever trust leaving my truck with, and he asked if I had 6 or 12 volts at the coil. I asked for a meter and went and checked and I've got 12. He said I'd have 12 ONLY under starting conditions and after that the resistor wire should leave 6 volts at the coil while it was running.

DOes that sound right? I trust this guy with my life but it just sounded really odd. If I do have 12 volts all the time then that's what has caused me to go through two brand new sets of points in a four month time period right? Could I have a coil issue?

Any opinions would be great.

[EyeH8the24]

get a cheap hei and be done with the problems.....

[Sinister]

[69C10@16]

Im going to after I start my job in a couple of weeks but for right now I can't. I'm gonna get a new set of points put in it but I also want to get it to stop frying them up too.

[Longhorn Man]

6-ish volts is right, and if it is getting 12 volts all the time, then yes, that'll fry the points.

[LockDoc]

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w/LHM. The coil receives 12 volts when starting and 6-8 volts when running. Voltage comes from the starter solenoid when starting (key in "start" position) and through a resistor or resistance wire when running (key in "run" position). For some reason you are getting 12 volts to the coil all the time and that is why you are burning up points.

LockDoc

[69C10@16]

Ok i found the yellow wire coming up from the starter. It ties into my resistance wire. The yellow wire to the coil ties into the resistance wire at the same point. I cut the resistance wire and turned the key to the "on" position. 12 volts. I had a friend crank the engine and while he was i had 12 volts from the starter. It was dead when he wasnt cranking. So, I went to O'reilly's and asked for a resistor to go from 12 to 6 volts and put it in line with the resistance wire between the keyand where the coil and starter tap in. I have 14.8 volts on the key side but I still have 11.6 on the coil side. Why didnt the resistor drop it enough???? Took it back and got another one. Same thing. Any ideas?

[WorkinLonghorn]

Any ideas?

See post #2 above. $46 from Whites Performance plus HEI plug wires,much easier starting,no maintenence.
As for the resister not working,I don't know but I think if you check the voltage at the coil with the wire hooked up and the switch on "run" it will show 6-8 volts,not sure but I'd check it this way.

[72lb4x4]

The purpose of the condenser is to keep the pionts from frying when they open due to the fact that the coil current doesn't want to stop flowing.

The condenser may be bad...

[69C10@16]

Im gonna go HEI when I get the money but right now I can't. I have been offered a job at O'reilly's and I just need to go through all the officialities of interview and all that before I can start but I was told the job is pretty much a sure thing. After that starts and I get a few other things payed for I'll say screw it and get an HEI distributor, slap that in and be done with it for good. I'll get me a set of good plug wires and a set of wire looms and no more problems for me. BUT, for the next month or so, I need my truck running like its supposed to. Ill double check the voltage at the coil but I'm pretty sure it's still too high.

[LockDoc]

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Heres the wire locations on the starter solenoid. You might check to see if they are on the correct terminals.

When you say that the yellow wire from the starter "Ties into my resistance wire" do you mean at the post on the coil or at a junction on the firewall?

Where did you cut the resistance wire? I wonder if maybe someone replaced the resistance wire with a regular piece of wire. It looks like the resistance wire should be a 20ga white/orange/purple wire.

When you asked for a "resistor to go from 12 to 6 volts" they may have given you a voltage drop that allows you to run accessories on older 6 volt autos that have been upgraded to 12 volt systems. You need to make sure that you are getting an "Ignition" resistor block.

When the key is "on" (not on start) you should have 6-8 volts on the wire from the ignition switch to the coil, and no voltage on the yellow wire from the solenoid. If you have 12 volts on the wire from the switch then I would say the resistance wire has been replaced with regular wire or the resistance wire is malfunctioning and needs to be replaced.

LockDoc

[IBAPIGFARMER]

I had the exact same problem..I have 8-9volts at coil. Had to put resistance block from o'reilly and rewired back into resistance wire.
My original resistance wire had 12volts also. Weird...You would think that if the wire was bad it would have more resistance not the same as the Batt. My resis. wire is the original and has not been replaced.

[Boog]

And on the flip side of this, when you finally do go with the HEI distributor you will need to replace the resistor wire to allow a full 12 volts to the dist. The HEI requires it.

[69C10@16]

Lock Doc - The two yellow wires, one from the starter solonoid and one from the coil, tie into a junction point on the firewall which was nothing more than all three wires soldered together at one spot. The wire that I though was a resistance wire is nothing like what you described though. Its white and looks like the insulation is a braided mesh and there was another black insulator inside of that. I cut the resistance wire about 12 inches from the fuse block and put in the resistor. Gerry at O'Reilly's handed me that block after I asked for a 12 to 6 volt block for my ignition coil so I assume it is the ignition type resistance block. When the key is in "on", not start, the coil has 11.6 volts. In "start" it has 14.8 volts. Oh and the diagram you made is exactly what I have. Everything checks out. Yet I still have 11.6 volts at the coil.

Boog - Yeah I know, everything I'm doing now will be blown all to h3!! when I go HEI in a few months but until I can do that, I gotta have something to drive.

[72lb4x4]

The ignition circuit goes through the coil and points. If the points are open, you will read 12V regardless of whether the resistor wire or straight "nonresistor" wire is used. That's because there's no circuit because the points are open.

Basic electrical thing: You always read full voltage on an open circuit.

I'd be looking at the condenser rather than redesigning the factory setup...

[ChevLoRay]

...and the condensor is a part of the points assembly. Make sure you don't cheap-out on that part of your ignition system. Good parts make good sense. I use NAPA, when necessary. Standard/Blue Streak was my go-to brand "back in the day". It's been so long since I used points, I don't know if they're even in business or available.

You can set the dwell angle to 30 degrees, while cranking, to be sure the points are set to the correct gap. If you don't have the flexible allen tool to do that, it won't be as easy. It looks like a screwdriver, with a flex coupling (like a spring) and a straight 1/8-inch allen on the end.