Compression test time! For all you guys who have never done one before. Here is the proper method. Cold engine, disable fuel injection, pull ignition lead, and then go at it. I like to do 2 rounds. 1 round with shorter crank interval and a second round with slightly longer crank interval.
EDIT: Some folks mentioned to run another test per the FSM procedure with engine at operating temp. On a factory "street" engine I always run compression tests cold so that the piston rings are not expanded. It gives me the best reading of what the compression is at worst case scenario. When the engine is warmed up the pistons/rings expand and you have better seal and better compression. For a commercial engine or race engine, always have to run the test warm since they are built "loose" by design. BUT, I am not very curious to see the difference. So I'll be doing a follow-up test and video with engine at operating temp and throttle at WOT. I'll post that once I get it done this week.
Step by step video for ya'll here on the first round of testing with engine at cold temp and throttle plate closed:
EDIT: Some folks mentioned to run another test per the FSM procedure with engine at operating temp. On a factory "street" engine I always run compression tests cold so that the piston rings are not expanded. It gives me the best reading of what the compression is at worst case scenario. When the engine is warmed up the pistons/rings expand and you have better seal and better compression. For a commercial engine or race engine, always have to run the test warm since they are built "loose" by design. BUT, I am not very curious to see the difference. So I'll be doing a follow-up test and video with engine at operating temp and throttle at WOT. I'll post that once I get it done this week.
Step by step video for ya'll here on the first round of testing with engine at cold temp and throttle plate closed:
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