I just finished running a compression test on my 89 6.2 chev pick up. all the cyclinders read good compression 360-380 except for one. the first cylinder on the driver side reads 0. I tested that cylinder numerous more times and it reads 0 most of the time but reads around 200-250 once every fourth or fifth try? any ideas? sticking valve maybe?

 

Or lifter , check rocker also .

 

Broken valve spring will also do that. I have a worn off lifter on my desk from a 6.2, the roller is completely flat and worn like a "C" with all the needles out of it.