Step 1 remove the fuel pump and fuel injection fuses. If the compression comes up markedly.
How To Do An Engine Compression Test Axleaddict
How to do compression test. This mixture must be placed under pressure in order for the engine to create any power. 40 psi or more. Now turn the key and crank the engine over for about 10 seconds. Turn the key as far as it will go in the ignition then release it. Disconnect the main wire to the coil and spark plug. The needle on the compression gauge will stay at the highest indicated compression reading.
Crank the engine two revolutions or so to spread the oil. Press the pressure release valve on the side of the gauge which will return the gauge to zero pressure for the next test. Then retest the cylinder. So you squirt the tablespoon of engine oil into a cylinder that is reading low. Adding oil to spark plug hole for wet compression test. Youre all set up now and ready to actually do the compression test.
After pulling in the air and fuel during the intake stroke the piston is now forced back up in the cylinder compressing that air and fuel mixture. Cylinder compression can inform you on how much wear an engine has on. The trouble is poor ring to bore sealing. With a compression tester a few hand tools and 20 minutes you can try this yourself. The engine will be running throughout the entire process. A compression test can also inform of an individual cylinder problem which can be repaired.
Crank the engine at least 4 times to complete the test. When youre done check the compression gauge to get the test result. This is the stroke in which you will be performing the compression test. Do this about 4 or 5 times without shutting off the vehicle at all. Double check that you disconnected the appropriate stuff so the engine doesnt actually start.