72CUTTY

so ive been working on my engine trying to locate the knock noise and find out exactly where its coming from. Definetly thinks its a rocker arm noise and i will remove the valve covers on Sunday. But yesterday night when i was looking for the sound i saw that 6 of my msd 8.5mm wires light up right at the spark plug. Is this bad? i already ordered new msd wires . Should i replace my plugs too? i replaced them about 4 months ago. I have the msd 6al box does that make a difference?

MDchanic

Yes.

No.

No idea.

Basically, there are two things that travel through wires, and they tend to be seen together most of the time: Smoke and Fire.

If the smoke or fire get out of the wires, then there's something wrong.

In your case, fire that should be getting to your spark plugs to make your engine go is getting out before then, which will lead to poor full (or near-full)-throttle performance and rough running, worse in damp weather.

I could put that in highfalutin' terms, but the basics is purty simple: current (electricity) and voltage ("pressure" or "electromotive force") that get out before their job is done aren't there to do their job.

You need to inspect your wires / boots for correctable problems and correct them if you can find them, otherwise get new wires.

- Eric

72CUTTY

thanks! my wires dont hook up to the plugs easily anymore..I will go ahead and replace them this weekend

Beob

I have had sparks jumping on the outside of the plugs and turned out there was a problem with the plug. One time it was cracked porcelain. Probably wires but should also check plug gap and oil fouling.

cutlassefi

X2.

How old are the wires?

MDchanic

All good points. A gap that is way too big will cause voltage in the wires to rise higher than it normally would.
HOWEVER, this will expose preexisting flaws in the wires - good wires won't spark even with the plugs disconnected.

Cracked porcelain will spark, but if you look, it won't be the wire sparking.

- Eric

72CUTTY

So i changes my wires. Installed new msd 8.5 wires and i can see still a little arcing on 4 wires. Spark plugs seem good. I got ac delco. Any advice?