Cut off while cruising, won't start, help!
 

A little background. I have a 1990 with a boosted 1.6. Link engine management (which is why I put this here, if it's in the wrong place, sorry) that I've been driving for two years. I'll have the occasional problem with it, but rarely does it just break down. Most everything is stock besides the turbo setup. A few days ago, I put a brand new head on it, with a brand new turbo, new feed line, and some other hardware.

Also, this could be relevant, it just started happening. The last two cold starts, it knocked pretty loud for a couple minutes until stuff started heating up. It sounded like the low-oil lifter tick, but louder and you could feel it like a spun rod bearing.

So anyway, today I drove a friend out of town and let him drive back. Halfway back, I started feeling something weird and looked over at the gauges. Everything was normal except AFR. 10-11 at 60 on the highway. About 2-3 seconds after I looked over it died. Wouldn't start, I had it towed, and I'm on my way to work on it now. The only thing I noticed was that with the engine off, and ignition on, AFRs were bouncing around 12-15 lambda. Normally as the fuel dissipates, it leans out slowly.

After it was towed, I briefly inspected it; all I noticed was the insulation on the wires to the o2 sensor was melted through. I thought maybe a couple wires had melted together and shorted out, so I'm going to cut and splice the harness, but that shouldn't cause no start. It's an AEM UEGO kit wired into link.

Any ideas? I could really use a solution haha.

What do the plugs look like? I think oil in the combustion chamber can show a rich mixture like that.

I found the problem early this morning. When we put my head on, I has a friend throw the cam gears on, and didn't think to tell him to put loctite on the bolts. Basically they backed off, I replaced the sheared exhaust cam, and it's running great now. Gotta love that non-interference.