I had a little problem at Nelson this weekend and I'm wondering if I am screwed. '86 ITC Civic, stock carb.

I lost a cylinder during Sunday qualifying. Pulled the plugs and the number 4 spark plug is shown below. The other plugs were fine, no metal, very clean and nice.

When I pulled the fuel filter it was full of tank foam. So my thinking is that I lost fuel pressure and it went lean.

Would it make sense that this was the cause? Does it make sense that only #4 was affected?

It seems to me that when we swapped plugs a few weeks ago at ORP that 4 had the least carbon and 1 had the most. Am I making that up, or is it normal for 1 to be richest and 4 to be leanest? If so, does it make sense that only 4 would be affected?

Now the worse question: how screwed am I and what do I do about it?

I ran the car about 1.5 laps of qualifying after the plug went bad. I didn't immediately realize I was down on power, I was getting passed by fast cars and I was trying to stay out of the way.

Replaced the bad plug and the car starts right up. Seems to run fine. I decided to go ahead and run the race and hope for the best. I started the race, the car seemed to run fine and then on lap 2 I lost power again. I figured I was completely screwed, so I went straight to paddock. Doh! The wire from plug 1 had come off. Put it back on, runs ok again.

So, the car ran hard about 3-4 miles after the plug was burned. It warmed up a good 10 minutes in grid, ran a pace lap and about 1.25 miles of hard running before the plug wire came off. Then ran the rest of the lap and into paddock.

What do I do now? How damaged is the head likely to be? Not to mention the piston and cylinder walls. And what, if anything, should I do about it? Is the damage already done? Is there any point in pulling the head off to stare at the damage? Or do I just run it and hope for the best?

Thanks in advance for any advice you can give.