I tested the compression of each cylinders of my 2GM20F. Cylinder #1 270psig and Cylinder #2 250psig. These numbers seems way too low as expected is 370-450psig. I should have squit some oil into each cylinders before trying again to see if the pressure will come up. If it does I suppose it means my piston rings are wore. But I forgotten about this step. I'll schedule anither day for this test again.