spark arcing

IGottaSy

Active member
Not on the Sy but could happen... You guys who know what's up, will you post up what you think/know causes spark to arc all over?? Please correct my errors.:tup:

Been reading and came up with these

1. Lean condition
2. Poor grounds
3. Bad plugs/wrong plugs(heat range?)
4. Plus gap too large
5. Bad/cheap wires
6. Bad/weak coil
 

IGottaSy

Active member
Re: spark arcing

If you see arc, the failure is going to be where you see the arc

Not actually. For example, too wide a gap might cause arcing at any spot on the wire/distributor cap if it is close to a ground because electricity takes the path of least RESISTANCE.
 

ajt86

Member
Re: spark arcing

The cap and wires are insulated. There is no way too wide of a gap is going to cause spark to go through the insulation on the wires unless theres a failure in the insulation.
 

Don W.

Stab it and steer it
Re: spark arcing

Yes and no. More info needed. What does "spark to ark all over" mean?

Without more info your list changes to:

5 becomes 1, 4 become 2, 3 remains, drop the rest.

Believe it or not I once saw a 2 cyl stationary motor (Wisconsin?) with points and coil ign (no magneto and no electronics back then) run with the cap off the dist. Yup watching the rotor turn and the motor running.

What was happening was the cap was bad and the center, coil, term was arcing out to each plug term in the cap. Firing both plugs at the same time every time. (Today that would be called wasted spark.) Replace the cap and it ran like it should.

Moral? Check and verify everything, twice, and take what the other guy said with a grain of salt.:rotf: That includes me...
 

IGottaSy

Active member
Re: spark arcing

Spark arcs down the plug wire itself. On other wires, spark arcs to head, dipstick, other wires, etc.

Wires and spark plugs are new, BTW. No trouble codes stored.

Oh, and all plugs have a "coronal discharge"; normal, they say. I think that is the term. I have added 2 more ground to chassis and cab. Problem persists.

Idles erratically. surges. Pumping throttle helps. Spraying cab cleaner into throttle body seems to stabilize rpms.
Used carb cleaner spray to find a couple of vacuum leaks which I fixed.
 
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IGottaSy

Active member
Re: spark arcing

The cap and wires are insulated. There is no way too wide of a gap is going to cause spark to go through the insulation on the wires unless theres a failure in the insulation.

I have read it will happen. Recommendations are to keep ground sources at least 1/2" away. Also, wires braided together to keep them away from hot exhaust or moving parts can arc into each other. It all deteriorates especially with 50K or higher voltage going thru them- the norm for aftermarket coils.
 

Don W.

Stab it and steer it
Re: spark arcing

I have read it will happen. Recommendations are to keep ground sources at least 1/2" away. Also, wires braided together to keep them away from hot exhaust or moving parts can arc into each other. It all deteriorates especially with 50K or higher voltage going thru them- the norm for aftermarket coils.

X2 Wires tied together sets up voltage in the adjacent wire. Setting up crossfire. The correct plug may fire but the wrong plug can fire also. Spooky to track down. If the wires have to cross, like at the dist try to make it at as much of an angle as practical. Also use wire separators.

I did some poking around and found these. Interesting.

Corona on wires:

https://answers.yahoo.com/question/index?qid=20100410224658AA5JbRR

Corona discharge:

http://www.ngk-sparkplugs.jp/english/techinfo/qa/q17/index.html

Fake plugs:

http://www.ngk-sparkplugs.jp/english/techinfo/fake/index.html
 

IGottaSy

Active member
Re: spark arcing

Fuel pressure is almost non-existent. Removed fuel line and it spits intermittent streams of fuel which don't even register on the fuel pressure gauge!
It's a TBI system BTW. Now to find a decent pump. I'll post if this helps with the arcing spark (misfire) issue.
 

IGottaSy

Active member
Re: spark arcing

Update:

finally got new fuel pump yesterday and installed this morning. Wired it through truck's existing ASD relay. Had to do homework on Dodge wiring, ugh! Runs a whole lot better. Need to adjust IAC. Idles at 1500rpm. Waited for darkness to check spark arcing. 2 spark plugs are showing corona thingy. Two wires are arcing. Before ALL wires and plugs were "leaking" spark. More fuel made a difference. I like people who post helpful stuff on the internet bunches!! even if they don't like me back. Will upgrade plug wires and plugs to different stuff to fix issue eventually. Too many bugs to work out. Time to go work the Sy instead.
 
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