GM / General Motors: compression test

In article <MPG.1a05be41df6fd40989686@shawnews>,
bob <bob@his house.ca> wrote:
 

If you're doing a cranking compresion test, all of the sparkplugs
would be removed, throttle wide open and fuel and spark delivery
disabled.
If you're doing a running compression test, only the sparkplug
for the cylinder being tested would be removed.
If you're doing it electronically, no sparkplugs need to be
removed.