That's probably the best position, although I have never seen any instruction on that on any coil, it does make sense.
Arcing across coil terminals
- Thread starter smokinnjokin
- Start date
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That's probably the best position, although I have never seen any instruction on that on any coil, it does make sense.
Some of the mopar ones have it in the box, not all though.
smokinnjokin
Well-Known Member
Update/clarification. I physically observed the arcing between the positive and negative coil terminals and the primary wire. I did not observe any arcing from the coil to the distributor, however based on the carbon tracks on the wire it seems likely that was happening as well. The coil was that close to the distributor because the negative lead would not reach. I extended the wire and moved the coil back. Also double checked point gap, its at 0.014". Coil showed .6 ohms between terminals, and 9.5k from center to positive. Within specs for the UC-12x. I checked the tower very closely for cracks or carbon tracks. Very faint carbon deposits, but no cracks.
2 of my plugs were badly fouled, so I replaced them. Car runs fine now, don't see any arcing. I won't be sure everything is good until I have another 100+ degree day and the car has run and then sat for a while in the sun (highest under-hood temps). This is when problems always pop up.
2 of my plugs were badly fouled, so I replaced them. Car runs fine now, don't see any arcing. I won't be sure everything is good until I have another 100+ degree day and the car has run and then sat for a while in the sun (highest under-hood temps). This is when problems always pop up.
67Dart273
Well-Known Member
HAVE YOU CHECKED the wires/ plugs for opens? OPENS in the secondary circuit?
smokinnjokin
Well-Known Member
The plug wires are new, no breaks or visible damage to them. How do i check for ‘opens in the secondary circuit’?
You mentioned new wires. I see the new wires (grey colored) and a not new coil wire (yellow) with discoloration at the coil end. Just sayin'
Another thing to make sure of. Make sure all of it is good and CLEAN. Up to and including grease from your fingers. Anything the spark can use as a conductor, it will. Also, did you use dielectric grease in all your plug wire connections? That why you use it. To act as an electrical "seal" if you will to aid against arcing.
With plug wires new doesnt always mean good.
The point gap should be .017''
Before you push in the coil wire, pull the boot back. That way you can feel the coil wire 'snap in'. then push the boot on.
I'd replace the coil. ---- And get a higher quality dist. cap and rotor from the same manufacturer. The old tan colored Mopar caps had vertical ribs on the inside. And as somebody said, replace the coil wire. It may have been damaged.
Before you push in the coil wire, pull the boot back. That way you can feel the coil wire 'snap in'. then push the boot on.
I'd replace the coil. ---- And get a higher quality dist. cap and rotor from the same manufacturer. The old tan colored Mopar caps had vertical ribs on the inside. And as somebody said, replace the coil wire. It may have been damaged.
Preach on brother!
smokinnjokin
Well-Known Member
Darn, now im wondering if the new coil wires are the cause of my HEI conversion attempts not working. What are some good coil wires that are reputable?
67Dart273 is correct, the problem is an open circuit in the secondary. That causes the voltage to build up until it arcs somewhere. You need to have your car tested on an ignition scope, it will show the problem instantly.
smokinnjokin
Well-Known Member
Where would I look for such an animal, speed shops? Never seen one before at a garage.
Seriously? Are yall suggesting this guy buy an oscilloscope for what's probably gonna be an under ten dollar problem? LOL
Lol nope but I linked one I have been watching here. A multi-meter set to ohms to start with would probably get him a good idea what is good and what is a problem.
I would love to have one myself, but of course now, the market for "vintage" shop equipment has drive the prices up.
Last one I had sold for 500 at Carlisle. Still have my wall unit and one portable. Wish he was closer I would look at it for him
I have always wanted the little Sun unit that was on a cart and about the same size as a VAT40. I want a VAT40 too. LOL
Vat 40 are all over craigslist. 50-600 range. scopes you just have to look for. I have a older sears that runs off of 12 volts. Great unit and small.
just a pic off the net
just a pic off the net
Got to admit that's a sexy looking Mac scope. I sold a handfull of those in my day. They were good stuff.
Toolmanmike, I really love my Mac scope. I've found a lot of bad ignition parts, alternators, and fuel injectors with that thing and made a lot of money.
I realize most people can't justify buying a scope, but when you have ignition problems, you need to find a shop with one and have them troubleshoot for you.
You guys have spent 2 days guessing at what the problem might be while someone who can read a scope could find the problem in about 2 minutes.
I realize most people can't justify buying a scope, but when you have ignition problems, you need to find a shop with one and have them troubleshoot for you.
You guys have spent 2 days guessing at what the problem might be while someone who can read a scope could find the problem in about 2 minutes.
KitCarlson
Well-Known Member
Got here late. I tried to read everything may have missed something. As others say visual inspection, and new does not aways mean good. Really difficult to see tracking .... you also have to know what it looks like. It has metalic glint, may need bright light and right angle. Once tracked, never quite as good, even with cleaning. Wear nitrile gloves, sweat is a good conductor. Especially when handling plugs,cap, rotor, cables.
Use an Ohm meter, go from cap terminal, all the way to plug tip. I do that when installing new wires. Longer wires will have more resistance, but all shold be in ballpark. Trim excess condutor tail past, where terminals crimp on. Do not cut into sheath insulation. Plug wires usually need work prior to install.
Resistance plugs are common used with COP, not needed with resistance cables.... using then may increase arc over.
With the popping noise, how often? One of 8, all 8, 2 together followed by delay? Knowing that helps diagnose.
Use an Ohm meter, go from cap terminal, all the way to plug tip. I do that when installing new wires. Longer wires will have more resistance, but all shold be in ballpark. Trim excess condutor tail past, where terminals crimp on. Do not cut into sheath insulation. Plug wires usually need work prior to install.
Resistance plugs are common used with COP, not needed with resistance cables.... using then may increase arc over.
With the popping noise, how often? One of 8, all 8, 2 together followed by delay? Knowing that helps diagnose.
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I would love something like that. Oh well. LOL
smokinnjokin
Well-Known Member
Plugs are autolite 66, wires are 8mm “suppression” so I assume both are resistor?
Looks like my center wire was the culprit, tracked and has small cut in sheath under the boot.
Looks like my center wire was the culprit, tracked and has small cut in sheath under the boot.
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