2013 compression test: spark plugs on or off?

[v8stang]

Wanna do a compression test on my 5.0 to make sure it's healthy.
Do I remove the plugs one at a time, or all at once?

Thanks

 

[itSSlow98]

Wont matter, i do them one at a time but it wont have an effect on the other cylinders.

 

[Shaun@AED]

Remove them all and disable the fuel pump (pop the inertia switch).

 

[cbrtrx]

Yes remove them all like Shaun said then test.

 

[5lho]

real proper is pull all plugs, prop the throttle blade open with a screwdriver handle and disable fuel pump.

This means low strain on the battery and starting system.

 

[v8stang]

Remove them all and disable the fuel pump (pop the inertia switch).

Thanks shaun. Im still having that low maf reading... I want to start eliminating options..
I had the tsb 13-6-15 done already btw

 

[v8stang]

Oh, and is this done on a warmed up engine?

 

[gmtech]

Closest to operating temp as possible to get the most accurate readings

 

[mechanicboy]

real proper is pull all plugs, prop the throttle blade open with a screwdriver handle and disable fuel pump.

This means low strain on the battery and starting system.

This. I put a battery charger on too whenever I can but if your battery is good it shouldn't make much difference.

I've always done them cold or just barely warm because I'm worried I'll mess up threads on a hot engine. Not saying it's right, just that's how I've always done it.