My Blazer started running like crap, so after checking the timing I pulled the distributor cap and rotor. My mechanical advance weights were overlapping. One was up on the other but the springs were still attached. After fixing this problem I ran it and it was fine, the power was back. I went to tighten the distributor hold down and I was about to shut the hood when I heard it lose about 200 rpms and i also heard a clicking noise. Right away i noticed that the #6 wire had melted to my exhaust manifold and was now arcing to it. Looks like new wires for Christmas. Anyway, I pulled the wire away and covered it with electrical tape. The next time I drove it it was running crappy about a mile down the road. I checked the wire and it wasn't arcing to the manifold, gotta be the mechanical advance weights again. How do I prevent this problem? If it's not one thing, it's another.