So I recently bought my 1987 Firebird Formula. Soon, I noticed arcing on the coil. Since the coil looked pretty old and rusted I went ahead and replaced it. The arcing still remained. I figured that it might be a bad coil wire. Since the previous owner had 7mm spark plug and coil wires in the car I decided to just replace them all with 8mm wires. Anyways, after installing them all, I notice that there's not even a coil wire in the box! Because my receipt was long gone I couldn't get the coil wire. So I went to another Autoparts store and got just the coil. He told me it was slightly used but would work fine. I waited until night and started the engine. Now the arcing by the coil is gone, but anywhere the coil wire rests against anything I can see blue electricity. Shouldn't the rubber sleeve on the wire insulate it against sparking? Is it possible he gave me a bad coil? Why is this happening and how can I fix it? Any tips or advice is appreciated.

 

If that coil wire is arcing, it's bad.

 

First of all ALL ignition wires including the coil wire should not be touching anything except plastic locating looms and the spark plugs. But a new coil wire shouldn't be arching, get a known good new one.

 

I took my coil wire back and got a new shorter one on warranty. Still, although this one doesn't rest against any metal, at night if I press it against the air filter housing I can see the blue arcing. Could it possibly be a problem with the distributor? The coil is new too.

 

I have davis 10MM wires and, some of them had touched the exhaust in a few places and cooked through to the spiral. At that point they would arch. After replacing them, they don't arch. Look for cracks in the wires, and do your best to keep them off of metal as eseibel67 had mentioned. You said 8mm wires so I would assume MSD or Accel? I had trouble with both of those cracking after a short time due to the heat shields being off of the exhaust when I fit the headers.