Hi,
I have problem with spark plug wire breakthrough.Just looked under hood at dark garage,and there is light show at engine comparament.Few wires have breakthrough at boots and causes rough idle and high HC emissions.
My ignition setup is:MSD pro-billet distributor #8366,MSD blaster coil#8226,MSD super conductor 8.5 wires,MSD 6A ignition box,AC Delco copper plugs.Wires are one year old,and plugs are brand new.Plug gap is 0.055".Are my plug wires so low quality that they are toasted at one year old?If cause is defective plug wires,which brand wires shoud I buy next?

Thanks,
Jari

 

I would buy new plug wires. MSD is hard on wires. The price you pay for the extra spark.

 

Should I buy ACCEL 300+ Ferro-Spiral Race Wires or MSD 8.5mm Super Conductor Wires.Any difference between those two?

 

Either set would be good. I don't see much difference.

 

Promlem not solved.I have replaced plug wires from MSD 8.5 to Accel 8.8 300+,and replaced cap and rotor and new coil.Plug gap reduced from 0.055" to 0.04".I tried also whitout msd 6a box,no differece.There still breaktroug at plugs 3,7,4,8.Funny thing is that brektroughs are at same plugs that before ignition parts replacement.
If I start cold engine,there is no breaktrougs at first ~30seconds.After that there is visible spark between plug hex and spark plug boot.
Ideas???

 

You could always try with dielectric grease but it sounds like there may be something wrong with those plugs so try to swap them.

 

I have tried dielectric grease,it makes breaktrough also with that.Current plugs are AC Delco r42lts(few hundred miles driven).Previous were Champion rs12yc.It makes samekind breaktrougs with Champions also.What do you like NGK TR55IX iridium plugs?

-Jari-

 

Try closing the plug gap to 035.

 

Just swap plugs.Now there is new set Champion rs12yc.Gapped them to 0.035".Seems to work,no breaktrougs.What do you think,is it so that 0.04" gap was too much?
Thanks for help.

 

.04 could have possibly been to much, i've had mine gapped at .035 and has been running great