I did a compression test on my motor this morning along with changing plugs etc, and it resulted in all of them being around the 240 psi range. The fuel pump was unplugged, the cylinders had no oil in them, and I did it with the throttle body open and the motor was warm. Question is....isn't my compression supposed to be around 180? What's happening? I looked inside the little spark plug hole with a flash light and it's super clean and silver looking. I'm baffled. Someone explain this to me.

 

Might be a long shot, but what brand and how old is the gauge.

 

Lol the gauge works. Just used it on my 240sx and it was perfect on point

 

You don't really know that, and even so, what's most important is that compression is even across all the cylinders. Absolute number is much less important.