Compression on 5.7 EFI
#2
dumb question, but I've only done compression checks on 2 stroke motors with kill swtiches, but what is the best way to disconnect the coil to avoid sparking/coil burn out when doing this test?
Please be specific, I'm in learn mode here!
Please be specific, I'm in learn mode here!
#7
Registered
On an engine equipped with the Delco EST distributor I usually remove the two harness connectors at the distributor, for T-bolt systems, I just take the wires (purple) wires off the positive side of the coil. Just removing the coil wire is not a good idea.
For a good compression test you should have a fully charged battery and the throttle plate wide open. It's ok to do it on a cold engine. You probably should see about 170-180PSI on an EFI small block. Big block would be more in the 145-165PSI range.
Dave
For a good compression test you should have a fully charged battery and the throttle plate wide open. It's ok to do it on a cold engine. You probably should see about 170-180PSI on an EFI small block. Big block would be more in the 145-165PSI range.
Dave