My 88 pickup has zero compression in cylinder #3... Before I go any further, what's the proper procedure to do a leakdown test and what do I look for? Cylinders 1-2 are 160, 4 is 180. No oil in water or vice versa. Thanks for the info.
How about a wet compression test to see if the rings seal up to give you a hint of compression? The leak down test will also show zero so not much learned there.
I would probably look at taking the valve cover off and making sure the valve train looked right for the 3rd hole.