1. We prepare the car for work (see "Preparing the car for maintenance and repair").
2. We warm up the engine to operating temperature and turn off the ignition.
3. We take out the fuse of the computer and the circuits of the engine management system (see "Relays and fuses of the engine management system - replacement").
4. Turn out the spark plugs (see "Spark plugs for engines 2112 and 21124 (16v) - replacement" or "Spark plugs for 2111 and 21114 engines (8v) - replacement").
5. We install the compression gauge in the spark plug hole of one of the cylinders.
Note. On an 8-valve engine, the operation looks like this:
6. Fully open the throttle.
7. The assistant turns on the starter for 5-10 seconds.
8. We remember or write down the readings of the device.
Similarly, we measure the compression in the other three cylinders. For a serviceable engine, the compression in the cylinders must be at least 10 kgf / cm², and the difference in compression between the cylinders must not exceed 1 kgf / cm².