Arcing at the plug boots
Thread Starter
Safety Car
Joined: Dec 2005
Posts: 4,270
Likes: 20
From: Central Michigan
Arcing at the plug boots
Came back from a short cruise around the neighborhood, and was checking out the engine when I turned the lights out checking for arcing...and sure enough the wires are arcing right at the plug....all eight of them
Let the engine cool a bit, removed the boots and applied dielectric grease to each boot....same result
There's a weak link in the ignition system somewhere, but before I go buying parts I want the Forums opinion on this
The System:
MSD tach drive distributor
6A box
8mm MSD Heli-core wires
AC 41-629 plugs gapped at .035
Blaster 2 coil
Everything is about eight years old with maybe 6-7000 miles on them except the plugs, cap, rotor which are ~ 3 years
Any suggestions?
Let the engine cool a bit, removed the boots and applied dielectric grease to each boot....same result There's a weak link in the ignition system somewhere, but before I go buying parts I want the Forums opinion on thisThe System:
MSD tach drive distributor
6A box
8mm MSD Heli-core wires
AC 41-629 plugs gapped at .035
Blaster 2 coil
Everything is about eight years old with maybe 6-7000 miles on them except the plugs, cap, rotor which are ~ 3 years
Any suggestions?
Race Director
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Pro
Joined: May 2011
Posts: 581
Likes: 5
From: BC
The weak link is where they are arcing. It is possible that you have too wide a plug gap causing a high firing voltage, too high for the plug wire insulation/boots, but I would think you are on top of that kind of thing and they would have to be pretty wide for them to exceed the insulation capacity of a good quality/good condition plug wire and boot.
Replace the boots and/or wires with a better quality silicone boot.
Steve g
Replace the boots and/or wires with a better quality silicone boot.
Steve g
Thread Starter
Safety Car
Joined: Dec 2005
Posts: 4,270
Likes: 20
From: Central Michigan
The weak link is where they are arcing. It is possible that you have too wide a plug gap causing a high firing voltage, too high for the plug wire insulation/boots, but I would think you are on top of that kind of thing and they would have to be pretty wide for them to exceed the insulation capacity of a good quality/good condition plug wire and boot.
Replace the boots and/or wires with a better quality silicone boot.
Steve g
Replace the boots and/or wires with a better quality silicone boot.
Steve g
Would the age/exposure to heat of the wires be an issue rather than mileage?
Any recommendations for a good wire/boot combo?
Pro
Joined: May 2011
Posts: 581
Likes: 5
From: BC
No, a .035 gap is not going to be the problem. While high resistance in the wires will raise the firing voltage it's usually that they quit conducting when they fail rather than the voltage rising and the insulation factor at the boot failing.
Like so many rubber parts, age and exposure are far more important than mileage. I'd actually say that in most cases, mileage is of no consequence.
Steve g
Like so many rubber parts, age and exposure are far more important than mileage. I'd actually say that in most cases, mileage is of no consequence.
Steve g
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I would replace the wires. If the arching is at the boots the high heat from the headers has likely caused the boots to deteriorate, even if it's not visible to the eye.
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From: Toronto Ontario
Toronto Events Coordinator
I had this problem. Even thought the boots looked okay, upon much closer inspection, I found cracks in the boots. It was weird because parts of the boot were still soft, while other areas were hard and literally crumbled in my hands! You can buy replacement boots from MSD and change them out, at least that is what I did.
Melting Slicks
Joined: Feb 2001
Posts: 3,330
Likes: 13
From: Europe , Luxembourg
Hi
Had the same problem and replacing the wires solved it.
It is strange how long the arc can be, I saw up to 2 inch long arcs all across the plug boot and the engine still kept running.
Seems to be only a part of the spark that bypasses the plug gaps.
I also was under the impression that the spark would take the easiest way with the lowest resistance, but this seems not to be necessarily the small air gap of the plugs tips.
Rgds. Günther
Had the same problem and replacing the wires solved it.
It is strange how long the arc can be, I saw up to 2 inch long arcs all across the plug boot and the engine still kept running.
Seems to be only a part of the spark that bypasses the plug gaps.
I also was under the impression that the spark would take the easiest way with the lowest resistance, but this seems not to be necessarily the small air gap of the plugs tips.
Rgds. Günther
Thread Starter
Safety Car
Joined: Dec 2005
Posts: 4,270
Likes: 20
From: Central Michigan
Thanks for all the replies, looks like I'll be replacing the wires
Anyone see any reason why these wouldn't work?
http://www.summitracing.com/parts/MSD-31233/
I looked at replacing just the boots, but with what I have to go through to get to the wires, only to have them possibly be too short when I'm done....may as well replace all with new wires
Anyone see any reason why these wouldn't work?
http://www.summitracing.com/parts/MSD-31233/
I looked at replacing just the boots, but with what I have to go through to get to the wires, only to have them possibly be too short when I'm done....may as well replace all with new wires
Drifting
Joined: Oct 2007
Posts: 1,317
Likes: 22
From: Marina CA
Randy,
I used the Accel wires with the hard ceramic boots on the blue beast to cure the arcing problem. 1 and 3 are the worst with the Hookers and since they were installed, no more problems.
On another note, what was the energy part number on the urethane tranny mount you installed?
I used the Accel wires with the hard ceramic boots on the blue beast to cure the arcing problem. 1 and 3 are the worst with the Hookers and since they were installed, no more problems.
On another note, what was the energy part number on the urethane tranny mount you installed?
Thread Starter
Safety Car
Joined: Dec 2005
Posts: 4,270
Likes: 20
From: Central Michigan
Randy,
I used the Accel wires with the hard ceramic boots on the blue beast to cure the arcing problem. 1 and 3 are the worst with the Hookers and since they were installed, no more problems.
On another note, what was the energy part number on the urethane tranny mount you installed?
I used the Accel wires with the hard ceramic boots on the blue beast to cure the arcing problem. 1 and 3 are the worst with the Hookers and since they were installed, no more problems.
On another note, what was the energy part number on the urethane tranny mount you installed?
Had to look up the mount on the ES website since I threw the box away
3.1108 G is the number
Drifting
Joined: Sep 2006
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From: Columbus MN
Thread Starter
Safety Car
Joined: Dec 2005
Posts: 4,270
Likes: 20
From: Central Michigan
Race Director
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From: California
Thread Starter
Safety Car
Joined: Dec 2005
Posts: 4,270
Likes: 20
From: Central Michigan
MSD would probably sue'em
Last edited by 682XLR8; Dec 13, 2011 at 12:20 AM.
Thread Starter
Safety Car
Joined: Dec 2005
Posts: 4,270
Likes: 20
From: Central Michigan
OK, Accel ceramic boots it is.....when my order from Summit gets here tomorrow, right back to Summit it goes, after I take my new plugs out of the box and an updated order goes in...
and an updated order goes in...