ok 92 F150 with a 302, it doesn't really matter but this is a new motor with just a couple thousand miles on it....had this same arcing problem with the old motor too fyi

at night, while the motor is running... i can see little bluish sparks where the wires connect to the plugs on all cylinders....furthermore, there is an occasional spark from the coil's primary to secondary winding, and the coil wire arcs continuously where it is touching the brake booster line (which is really weird since the brake booster is rubber!)...all this translates into a semi-rough idle, and a stumble upon acceleration about 1/2 the time

I've tried autolite, accel, and now motorcraft wires, with no difference....I have new, properly gapped, motorcraft platinum plugs...cap and rotor are aftermarket, but are fairly new, slightly worn, but not bad at all....coil is your basic off the shelf aftermarket version

obviously I could go buy a more expensive cap, rotor, and coil to go with my motorcraft plugs/wires....however, i'm worried that i have some kind of a grounding problem instead, i don't know why or how, just a hunch....

as it stands right now, the current is being divided between the plug itself and the block, hence the arcing... if I replace the aftermarket parts i have with higher quality products, this would in theory increase my spark output, which would only result in an increase in voltage across BOTH paths to ground that the spark is currently utilizing

maybe i'm not understanding something, help!

 

was the coil replace with the right amount of voltage etc and matched the right wire gauge for that coil cause if you replaced the wires then the coil is wrong and or the distributor is not right this is an easy engine mainly mecanical arcing is bad and will cause what you have make sure all the wires are properly spaced and just wondering . . . . have seen this mistake before aka my dad your running an altenator and not a magnito right cause if your using a magnito for power aka save weight raceing crap etc then yeah that would cause arking if the wires are to close and to much power now the only thing i can think of doing is try to measure the amount of voltage coming out of the coil and see if its correct for the wires that is since you bought an aftermarket one it should say on the box well good luck

Tom

 

yes i have an alternator, this is a stock work truck, no racer here

wires are properly spaced, i've used a lot of those rubber and plastic separators everywhere, distributor is less than one year old too

just put on an msd coil....still see faint blue arcs on all cylinders at the block (at nighttime) and still have the occasional stutter at idle and on low to medium throttle, if i give it more gas it goes away after a couple seconds, then comes back a little later on

i think i'm going to add another ground wire or two from block to frame, i'm scratching my head here??

 

ground the f*** out of it! but some of those 2.5 inch wide ground straps!

 

you're right you have a grounding issue problem...I would start by cleaning all the grounds...I would also try putting the old coil back on...or try a different one for giggle...

if the wires short in the coil it will arc to ground easily...

 

Did you ever get the arcing to stop. My 89 is doing the same thing sorry i know its an old thread

 

There are actually quite a few ground straps (or bridges) installed at the factory. When engines are swapped, they always seem to be scattered about the floor after the swap is thought to be completed. Trust me, Every single one is there for a reason. Just cause we can't figure out why, isn't a good reason to omit them. If Ford thought they could get away w/o them, you never would have seen them to begin with. I would get the wiring diagram for your engine & truck and try to recreate the same grounding system. It is in fact a system. I'm surprised that's not the only problem your experiencing. If enough of them are missing, sometimes they start acting like they're possessed. Just plain bazaar stuff.

 

Hello,
Did you ever solve your arcing problem.. I have the same issue.Thanks, Mike

 

you didnt read our post with the info to fix it...?

 

did you solve your problem? my 94 w/ 302 and 163 thous. arcs at all the wire /plug
boot new wires plugs still arcing new coil and arcs sometimes . I could use your experience. thanks.