This is an instruction on how to perform a compression test on an engine.
I will be using this motor, an S13 Red Top SR20DET.
Here is what I will be using to perform the test.
This is a Compression and Vacuum test kit
Step 1) You will need to warm the engine up to operating temperature
Step 2) Shut Engine off
Step 3) Begin by disconnecting the coil pack connectors
Step 4) Remove the Coil Packs or Spark plug wires
Step 5) Remove All Spark Plugs
You should remove all of the spark plugs because having only one out and the rest in creates a resistance because of the pressure in the cylinders that have plugs, this can slightly throw off your readings.
Not to mention you can go very easily and quickly between cylinders.
Step 6) Remove Fuel Pump Fuse
Step 7) Disconnect Fuel Injector Connectors
The reason is that even though you took the fuel pump fuse out, the Injectors will still pulse and spray whatever fuel in the system into the cylinders and wash them out.
Step 8) Screw the compression extention adaptor into the spark plug hole
Step 9) Connect your compression gauge up to the adaptor
Step 10) Have someone crank the engine 8-10 pulses or until the gauge has stopped at it’s compression number.
I had 150PSI in the front 2 cylinders and 145PSI in the last 2, which passed specs.