1992 2.3l, 30psi dry/40psi wet compression? (updated info)

[nameiztaken]

Update regarding a previous post:

Bought a 2.3l ranger for dirt cheap and found 30psi compression on Cylinder 1, 2 and 3. Cylinder 4 has 170psi dry.
Compression rises 10 psi on all cylinders when oil is added (wet test).
Seller states he was driving it up a hill on a "hot day" and the engine began making a "noise" and died. He mentioned something about replacing the timing belt, but I'm unsure if he replaced it.

I can't run the engine without buying a harmonic balancer and crankshaft hub, which I don't want to buy until the compression is fixed.
Any ideas are appreciated.

 

[RonD]

Plan on having the head redone, i.e. valve job pressure tested and surfaced

So pull the head and have a look at the tops of the pistons, they should be fine but you won't know for sure until you have a look

Wet test ALWAYS goes up, in all cylinders all engines, the fact it only when up 10psi tells you the Valves are the issues, "probably" not the pistons and rings, but you will have to look and go from there

You could rent a borescope, video camera on the end of a snake, it fits down spark plug hole to view any damage inside cylinders