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Purple lightning under the hood?

Featured Replies

Okay so its not literally purple lightning but thats what it looks like. My coil is arcing between the posts with purple "lightning". Ive never seen this before nor do I know how to diagnose this.... any ideas as to whats wrong? Is the coil itself bad or is it something I can fix? i.e. is it not grounded properly etc.... 

thanks for the input! I just wanna get my 81 sedan back in tip top condition so i can get it to the show this coming year. :D

  • Author

like spark plugs and spark plug wires? Because i just replaced those earlier this week :P or are you referring to the wires and plugs on the coil?

Spark plugs and spark plug wires are what we were saying.

 

What brand plugs and wires?

 

Really shouldn't be doing that with new parts. Make sure all wires are fully seated on coil, cap, and plugs.

 

Would also suggest that you clean all of the ground wires. Main battery cable to engine, small wire battery to body, one from spare tire shelf to trans. If yours is SPFI there is another ground or two.

 

Something is causing a lot of resistance, thus the arcing at the coil. Could be a bad coil high tension lead too,the one that goes to the disty. New or not, it happens.

... or are you referring to the wires and plugs on the coil?

 

I bet that some of those wires has cracked plastic insulators, so, change them or isolate them with enough isolating tape could be the Solution; if you could determine that the source of the purple arch is on said area.
 
Kind Regards.

ditto! if you are arcing from coil to terminal, you have a bad coil wire or bad ends in it. it can't make it to the dizzy so it's going to the nearest ground it can. this is BAD for your cars electrical to have the kinda power surging into it, and bad for the coil. 

 

if you still have the old wires, swap it out with the new coil wire and recheck. otherwise return the wires for a new set

  • 1 month later...

I have this same problem. Have already done the suggested. still "purple lightning". I called it the light show. Still havent figured mine out.

Thebr0wn0ne just wondering if you have looked at ur plug hexes(where u would put a socket to remove the plug) to see if you have any arcing there

How about a new distributor cap? A bad cap can act like a bad coil wire, if the pickup electrodes are badly worn.

I have this same problem. Have already done the suggested. still "purple lightning". I called it the light show. Still havent figured mine out.

 

 

What exactly have you done? details

I have replaced plugs, cap, rotor, plug wires(twice) i have cleaned the ground on the front passengerside head. cleaned ground from batt. to body. added a ground from back of motor inbetween bellhousing to body. the pickup being worn makes sense. mine just went out. still waiting on it. once i get it replaced ill see if it still happens.

Bosch everything except plugs. plugs are nkg BPR6ES11 the pick up that i ordered is a filko brand

Edited by 91 subaru

Just for S&G try a BR6ES, A BPR6ES projects farther into the combustion chamber,And might have more resistance than the ignition system likes causing your arching.An EJ on the hand takes a projection plug to reach the combustion chamber.

The high voltage from the coil will seek a path to ground through the least resistive path it can find. Normally that is through all the high tension wiring, through the air gap of the plug, and to ground that is provided through the plug body. The trouble could be due to a cracked coil as others have already stated or the main coil wire to the disty may be open. Once arcing has occurred through something it usually forms a path through it and that device will usually need to be replaced because the insulation has been broken down by the arcing. 

I hope thebr0wn0ne is gettin all this. i feel like i hijacked the thread

  • 4 weeks later...

Oh, we all browse the repair threads. I've got one going now but I still jump around looking for answers in others' problems. We just don't use exact language so the same problem can show up and described entirely differently.

For instance, I'm here because I'm trying to determine if the distributor has failed, or the coil, or both in some weird way.

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