Compression test help

Just been to check a b18c4 engine that i might buy and did a compression test on it, car was warmed up to operating temp, pulled the 15amp ECU fuse, removed all plugs and did the test

Each cylinder was pretty much dead on 15 bar ( 217psi ) of pressure but once or twice we heard a popping noise, anyone know what this could be?? Searched online but cant see any true answers

As i was on the way home i realized we forgot to do the test with the throttle peddle on the floor, how will this effect the test if it did?

Thanks

You'll see higher numbers with the throttle open.
In terms of compression the c4 you viewed is in good condition.

ok cheers, i thought 217psi was quite high as it is

Any idea what the popping could be? it sounded like air pressure rather than a bang

Sometimes you get a "popping" noise from the other spark plug holes.
It's just the cylinder that's on its compression stroke forcing the air out the plug holes.

Yeah that makes sense, nice one for clearing that up