1988 Lebaron top end problem.

This neighbor of mine has an '88 LeBaron turbo and she flagged me down yesterday because her car was running like crap. It was running on 3 cylinders and when I pulled the plug wire for number 3, nothing changed, but there was good spark from the wire to the plug. Also...when revved to around 1500 RPM, it knocked really bad from the top end.

I'm guessing that she lost a rocker arm on 3 and it has no compression....sound like a safe bet? I'll pull he valve cover tomorrow and see what's up for sure.

Sounds reasonable. When you pull the v/cover, have a look at the installed heights of the valves. A bent valve that is not returning to the full closed position will let the rocker fall off. A tuliped valve that is pulled too deep into the seat or a stretched valve stem will collapse the hydraulic lash adjuster and could cause a compression loss/dead cylinder. And make noise when rev'd up. Good luck.