Lightning storm under the hood with pic.

[375instroke]

Car sputters when I get on it.  Plug wires looked OK.  Not dry burnt, or cracked.  Hard to find a dark spot anywhere in the city, but finally found one dark enough to see sparks, I kid you not, up to 3 feet long, traveling the length of the plug wires, and jumping from the high tension lead on the coil to both positive and negative posts.

[nvrbdn]

too bad the car was running bad, but it made an awsome pic!!!

[John_Kunkel]

and jumping from the high tension lead on the coil to both positive and negative posts.

Check for a cracked distributor cap.

[68 CHARGER R/T]

i had one of those issues in my mustang . couldn't figuire it out the ticking noise coming from it until night time . it looked like a led show in pitch dark,  because of a spark plug. there was a hairline crack in one of them which made a arc show under the hood   

[375instroke]

WTF!  New plug wires, cap, and rotor, and same problem.  How could a stock points ignition system do this?  I'm guessing a bad coil, like carbon tracked.  The high tension spark is going into the positive and negative leads, and creating a positive feedback loop for the voltage.  Any other ideas?

[wrench]

ignition coil delivers whatever amount of voltage it has to, to jump across the spark plug gap. Up to coil maximum output, which on a dodge point system is about 24000 volts. normal new spark plug voltage requirements are about 8-10000 volts, which old style plug wire insulation can handle. 24000 volts??? those plug wires have a hard time holding it in. Check or replace your spark plugs. they are the dominant factor in coil voltage output.

[Ghoste]

You're right about it making a great pic though.

[AKcharger]

 

waiting to see what the fix is

[daves68]

Time for a physics lesson. From the picture, it appears the wires from the distributor are running down the left side of the engine. Here's your problem and the easy fix - get some wire looms and separate them. Here's why. Follow this carefully- when plug wires are feeding 2 cylinders that are both adjacent to each other in the engine AND the firing order, the current in the wires causes an electromagnetic field around them and creates the phenomenon of induction firing, commonly called crossfire. In our Mopars, cylinders 5 and 7 are next to each other on the left side and in the firing order 1-8-4-3-6-5-7-2.  Put the loom separators in so that they run next to other cylinders instead of together. It's ok if they cross each other at an angle, just don't make any long, close runs. Newer high voltage systems just make the problem worse.  That's why Ma Mopar put those little clips there in the first place. A bunch of wires running all nice and straight and parallel looks nice, but can be a problem. You can run them parallel if there is enough space between them, it's the long, close touching thing that creates the field. Check out some street rods at the next cruise in.  Hope this works out for you. Let us know.
Dave

[tan top]

dont know if i drempt  reading this ( ) or i actually did read this decades ago but , grease /oil on plug leads can cause problems like that ... any one heard of this !!  or any insite to this !!  as for over the last 20 years , made sure i wipe all leads with  pannel wipe / paint shop degreaser  if dirty  
 let me know if i have a bus to catch    

[Tilar]

grease /oil on plug leads can cause problems like that ... any one heard of this !!

Absolutely. This happens to batteries that are disconnected and left on a bench or the floor. Some people claim that putting a battery on a concrete floor will drain it, this is not true. What drains it is the acid and dirt across the top and sides of the battery.

You can actually test this with a volt meter. Clip a lead from the tester to one post, and then take the other lead and run it across the top and sides of the battery and check out the different voltage readings you get. Sometimes you can see the voltage increase the closer you get to the other battery post.  Sealed batteries are not as prone to this as a vented cap battery.  The same thing applies in this situation.

[daves68]

Actually, oil/grease/etc can add to the problem, especially if the wires are either bargain basement cheap or old and dried out. However, in this pic it clearly shows the spark following the entire length of the wire, not seeking a ground, as would tend to happen with the earlier scenario. Note too how the blue line is confined to the area between the wires - thats induction.  Whats happening is voltage is reduced to both plugs so they each fire with a weak spark- works so-so at low speed. Jack up the cylinder pressure by stomping on it and the miss becomes more evident. That along with the increased RPM means more and faster firing and more crossfire. Separate, and clean, those wires and I will bet your problem goes away. You can see induction in action when you clip on the timing light to wire #1- It's picking up the current every time 1 fires to make the light flash.
Dave 

[b5blue]

For many years I ran NAPA's plug wires, with their lifetime warranty I would walk in with my receipt and exchange them as needed, it even got kinda fun to listen to them grumble and stare at my 12 year old receipt with all the exchange tickets attached while they looked up the inventory to get my new ones. After my rebuild not knowing the rebuilt dizzy they sold me was crap (bad bushings, mismatched springs and weights and such) Firefighter (Ron) recommended trying Firecore wires so I got them. Even with the (unknown to me at that time) bad dizzy the difference was remarkable! I thought about giving the brand new NAPA wires away to someone but chucked them in the garbage knowing I would just be passing on crap and not really helping anyone out, that's how big of a difference just using the Firecores made. One other consideration is plug gap, it greatly effects resistance the plug wires "feel" that leads to arcing.     

[tan top]

thanks guys for the info  , greatly appreciated   

[375instroke]

I do keep 5 & 7 away from each other as much as possible.  The problem is on the right side of the motor, too, and the same with new, clean, crappy NAPA wires.

[Cooter]

Yessir! Just cause they are cheaper and have a lifetime warranty, treat 'em like their 30 years old...Only way I'll go from now on is racing wires with loads of insulation....

[375instroke]

So what are good black wires?  All the ones I see are lame colors.  The motor's already orange.  Do I need to pimp it out even more?

[mauve66]

So what are good black wires?  All the ones I see are lame colors.  The motor's already orange.  Do I need to pimp it out even more?

lime green ought to do the trick

[terrible one]

So what are good black wires?  All the ones I see are lame colors.  The motor's already orange.  Do I need to pimp it out even more?

Firecores are black. Lots of happy customers here and I'm one of 'em!

[b5blue]

Yup! Honestly I HAD run NAPA wires on many cars for many years in the past and never thought I had problems, I'm such a cheap-0 it was kinda a big deal to pay that much, but better is better! I did drill out my holders for their larger diameter. Adding the matched components of a dist. set up for my engines build and the A688 kit from FBO (with the Firecores and NGK XR5 plugs) really "woke up" my engine nicely.

[firefighter3931]

So what are good black wires?  All the ones I see are lame colors.  The motor's already orange.  Do I need to pimp it out even more?

You can have any color Firecore as long as it's Black  They only come in one color or is that shade   

Do a resistance test on your plugwires ; if you're seeing more than 250 ohms/ft then trash them. 

My guess based on your sparkshow is massive resistance. I've seen up to 5000 ohm/ft from factory resto wiresets. 

Dave Dudek is running the 250 ohm 8mm Firecores on his 800hp Hemi and currently holds the FAST record. 



Ron

[b5blue]

Good to hear from you Ron, you forgot to tell him he can order them from you. (Thanks for getting me mine and recommending the XR5's' it all works great!) 

[375instroke]

Are stock wires 7mm?  The FireCore 7mm are orange.  How do the 8mm and 8.5mm fit with stock clips like these?  Do I hog them out for the larger wires and apply some black silicone where I cut through the rubber on the guides?  This is a stock '69 Charger R/T, by the way.  I don't need a bunch of race stuff on it, but I need something at least as good as original, and black.



They have a picture under their FireCore50 Chrysler 383/440 Factory HP Manifold OEM 8.5mm with the stock looking wire guides.







Then there is the FireCore250 Factory Fit 440 8mm (no pic)

...or I could get these:



but someone said they may be junk.

[Charger-Bodie]

The 8mm ones will roll in,but I doubt you get the 8.5 ones in,but maybe. Ive used the 8mm Firecores the 68 brackets and they were all fine. The only one I had to hog out was the little white plastic one that clamps all the way around the wire and alips into the bracket by the exhaust.


and oh yeah,the stock ones are 7mm.

[b5blue]

I just picked a drill bit the size of the new wires and drilled the holders holes larger.