Ok my ranger is a 93 with the 2.3L as you may have already figured out lol. oh it has 120,000 miles on it. Ok well I just pressure checked my engine and piston 1 has a pressure that varies from 70psi to 90 and all the other pistons 2,3 and 4 all range between 145-150psi. What is wrong with my engine? Is it possible I may just need a new head gasket or is something wrong with my valves etc. please help me. Ask me as many questions as you need to I am tired of my truck idling like crap.

You can do a leak down test to verify where the problem is. to do a leak down test you will need toget that cylinder on top dead center on compression stroke and presserize cylinder with shop air. To find leak listen for air escaping from exhaust (bad exhaust valve) intake or oil fill (bad rings or piston). just verify that both valves are closed when leak testing.

It's probably the rings.

To eliminate possible rings put a squirt of really heavy oil like a 40w in the cyl and redo the compression test. This will help give a really good seal to the rings if pressure jumps up then you have bad rings. Another tell tale sign of bag rings would be blueish smoke from tail pipe and excessive oil consumption.