compression test question (slightly off topic)

[turboaccordlx]

Thinking of how a compression test works....


During the test the gauge will climb then hold.

You have intake and exhaust. How will the cylinder build and hold pressure through the cycle if it can leave through the exhaust valve at a certain point...


Or am I completly off on this one

[lil_dcb7]

Thinking of how a compression test works....


During the test the gauge will climb then hold.

You have intake and exhaust. How will the cylinder build and hold pressure through the cycle if it can leave through the exhaust valve at a certain point...


Or am I completly off on this one

Huh?

just pull the fuel pump fuse(or fuel system related)

screw the compression tester in each hole (lol thats a funny sentence)

hold the key so the car turns over four times

and you should have your reading.

its not too complicated.

[NAiL05]

I think he is asking how it works. The reason it doesnt really lose compression when you are turning the motor is because there is most likely a one way check valve inside to prevent the reading from fading when the exhaust valve opens.

[cp[mike]]

the gauge has a check valve, thats why you press the button when youre done, to release the built-up pressure.

[lil_dcb7]

the gauge has a check valve, thats why you press the button when youre done, to release the built-up pressure.

yeah the first time i checked my compression i did that on accident and it scared the shit out of me