Help with compression tester

[rei-04]

I just bought this compression tester and it says on carburetor cars to tie a string to the carburetor throttle plates to keep them wide open, but I have fuel injected 5.0 and was wondering if I still have to do this? Also I am testing it without my upper manifold on, so that wouldn't matter anyways, right?? Any help would be great.

 

[TheUser]

i'm not sure how safe it is testing compression w/o the upper on. If you're fuel injected, all you should have to do is pull all of the plugs, insert the compression tester tightly into the desired cyclinder and crank until it stops increasing...I usually go 10 times or so.

 

[rei-04]

thanks for the info. that is reasuring to hear I was hoping I didn't have to do that. I have to take my upper manifold off and install these 24# injectors that is why I asked if I could just test it while it was off.