1996 Cherokee Low compression on all cylinders
 

I have a 96 Cherokee 4.0 it has a very small idle issue so I wanted to check compression.
Cylinder 1- 75psi and Cylinders 2-6 have 80psi. Honestly it runs really good other than the small idle issue but I'm not sure why the compression is so low.
Wet Test results- Cylinder 1-95psi and Cylinders 2-6 have 100psi.
Yes I had the throttle wide open. Could the cylinders really be that screwed up? It has 139k miles...

Use another compression tester.

I rented one from O'Reillys and checked my Jeep, said my compression was 60-75 psi. Yeah, no lol.

Went and got one from Auto Zone, 140-150 psi.