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Discussion Starter · #1 ·
It has been suggested to me that the cause of hbar's shudder is a really bad miss, caused by spark plug wires rubbing against the engine compartment walls and/or the exhast manifold. I was also advised that right angle wires would help. I want to see what sorts of wiring you kids are using.

Now I have no doubt that replacing the wires is probably something worth doing, but could it really be responsible for this sort of thing? It only seems to miss in first gear, and generally only when I get into the pedal. So most of the time there is no problem.

thankee
 

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You can check the condition of your wires pretty simply. You need a spray bottle of water, adjust the nozzle so it sprays a fine mist. At night, darker the better, start the engine and spray the water around the wires. If you are having a wire problem you will see and hear the current arcing to a ground.
 

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Its probably not your problem but plug wires #7 & #8 should not be routed side by side when coming from the distributor cap. on the wire holders Ford routed them as 7, 5, 6, 8 due to misfiring.
 

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Proper routing is necessary to prevent cross firing.
 

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Discussion Starter · #5 ·
slim said:
Proper routing is necessary to prevent cross firing.
I'd expect improper routing to cause a more systematic problem, where as mine seems to be somewhat sporadic (sp?). But I clearly know jack.
 

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Note to self. Make sure Reds wires to #7&8 are not parallel to each other.
 

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Cross firing occurs the most under load, like flooring it. Probably wouldn't
hurt to check if it's strung the way the Ford manaul says to prevent cross firing.
 

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That's not what is meant by "cross firing". basically, it happens when the wires ARE connected to the correct locations. When a cylinder fires an electrical current is passing through the wire, creating a magnetic field. That field effects wires and other magnetic fields around it. cylinders 7&8 just happen to fire back to back. So the magnetic fields on wires 7&8 can effect each other. (think of two magnets side by side). Keeping them as far a part as possible helps alleviate the problem. shielding the wires as helps.

Pratically this hardly ever happens, usually you have a break in a wire's insulation, a bad distrubutor cap or bad rotor.
 

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What are you disagreeing with? Cross firing can occur under load even with new wires.
Induction happens between conductors running close to each other.
 

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sorry, meant to reply to hbar, not you.
 

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Discussion Starter · #11 ·
manyc said:
That's not what is meant by "cross firing". basically, it happens when the wires ARE connected to the correct locations. When a cylinder fires an electrical current is passing through the wire, creating a magnetic field. That field effects wires and other magnetic fields around it. cylinders 7&8 just happen to fire back to back. So the magnetic fields on wires 7&8 can effect each other. (think of two magnets side by side). Keeping them as far a part as possible helps alleviate the problem. shielding the wires as helps.

Pratically this hardly ever happens, usually you have a break in a wire's insulation, a bad distrubutor cap or bad rotor.
I get the mechanics of it; I taught E&M at the college level in a past life. I'm just surprised the effect only appears *some* of the time. The induced effect doesn't have anything to do with the frequency of the oscillation, and the frequency is the only variable I can identify in this behavior.
 

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Just some guy
67 coupe, 69 Sportsroof, 86 hatchback
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Temperature and humidity can be factors. I have obeserved the "aura" of leaky plug wires on my motorcycle when riding at night. When riding through humid areas it was fairly pronounced. Later when riding through much more arid conditions there was no sign of this.
I've always understood that seeing such a glow meant you were overdue for new plug wires and replaced (and upgraded) them the first chance I got. That was some years ago and I've never seen the glow again. I've seen it more times on cars running in a darkened shop but that was just generally checking the wires, not conditions which aggravated the problems.
Duuno if this is useful info or not, just observations I've happened to have made.
 

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Craig,

I was having a similar issue before replacing my old wires. Here is my current set up.

The wires are Taylor 135 degree cut to fit wires.

The looms are Made for You verticle keepers.

http://i64.photobucket.com/albums/h179/68fastwilliams/FTImustangpics007.jpg

http://i64.photobucket.com/albums/h179/68fastwilliams/FTImustangpics005.jpg

http://i64.photobucket.com/albums/h179/68fastwilliams/FTImustangpics019.jpg

http://i64.photobucket.com/albums/h179/68fastwilliams/FTImustangpics006.jpg
 

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Discussion Starter · #15 ·
68fastwilliams said:
Craig,

I was having a similar issue before replacing my old wires. Here is my current set up.

The wires are Taylor 135 degree cut to fit wires.

The looms are Made for You verticle keepers.
http://i64.photobucket.com/albums/h179/68fastwilliams/FTImustangpics005.jpg
That's what I'm talking about!!
 

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If you want a little more bling....

http://www.ssstangs.com/gallery/albums/userpics/10043/normal_IMG_1732.JPG

http://www.ssstangs.com/gallery/albums/userpics/10043/normal_IMG_1127.JPG
 

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You guys are killing me. Those are some of the most beautiful engine bays I have ever seen. Do you actually drive those Mustangs? :eek:
 

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If it is only in 1st gear and only under acceleration, then I'd look at the points, rotor, cap and coil first. The coil is probably fine but a little grease on it with some rain mixed in and it will lose efficiency. The cap, too. If all that is ok, then yeah, check the wires. What kind of wires do you have?

Ditto on those engine bays. They are beautiful....
 
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