I have had my car running

[meton4u]

I have had my car running for years with a sr swap and its always pulled super hard, never smoked, never mixed oil and coolant, never over heated, etc. i put ras on it like 3 months ago and the head had zero sludge and looked great. Two days ago i gave my car a compression test and it was wayyy low but evern across the board. Yes the throttle was open. I used 2 different testers aswell. It was between 90 to 100 across the board. Could anything make this compression test wrong? It seems like my engine is spinning slowly compared to a normal car

[benarovi]

well you probbly did it wrong or used a shitty tester. if it was 90 to 100 it would run pretty shitty. how does it run esp under load

[h23]

Cold engine or warm engine?

[MadScientist]

First, Dry Test
Start engine and let ilde till opperating temp is reached
remove all spark plugs
remove fuse for injectors or unplug them.
place a rag over the cylinder holes so no deby gets sucked in, but will catch whatever gets blown out.
start with cylinder closest to the front of the car (aka #1)
install test gauge
step on the gas pedal to WOT and crank the car around 5-6 rotations
record # and repeat for #2, #3, #4 cylinders

#s should not be more than 10psi difference.

Second, Wet Test
same thing just add a tablespoon of oil before installing the gauge.

Your #s will be higher with the wet test because the rings are properly sealed as they would be if the engine were running.
Compare the Dry and Wet #s... they should be similar values.
If you have a randomly low Wet test #, you have a bad Piston Ring!!