Been having a dreaded p301, for some time now. It seems to come and go as it pleases. I had the plugs, wires, cap, and rotor all changed less than 10,000 miles ago (probably more like 7,000) and it has decided to reappear again. I pulled the #1 plug and noticed that about 1/2 of the center insulator seems to be burnt. Didn't have a chance to look at any of the others because it decided to rain again.

Here's pics of the plug:







Anyone know what would cause this?

 

Wrong plug maybe..Looks like the reach is too long.

 

That's kind of what I thought too, but they are AC Delco 41-993. At this point I'm about ready to trade it in and start over later when the blazer won't be my daily driver.

 

What are you working on?

Yeah they can be a real pain some times, and you only have 2 choices. Be really rich, or learn to do it yourself. lol

 

A poor quality tune up will cause this. Look at the quality of the parts installed and the routing of the plug wires. Were the pieces of wire loom put on the new wires like the old wires had? GM doesnt put that loom on there for looks. Its there for a reason. Good Luck!