How can the compression be measured properly?
Here is an advice from a renowned expert, the Director of the firm AB-Engineering, A. Khruliev, Ph.D.: When measuring the compression, observe the following rules: warm up the engine, and cut off the fuel feed. To do so, you can switch off the fuel pump, close the nozzles, or use any other methods preventing the feed of fuel into the cylinders. Turn out all the spark plugs. Selective removal of spark plugs, practiced by some service centers, is inadmissible since this increases the rotation resistance and spontaneously reduces the revolutions when the engine is cranked with the starter. The storage battery should be fully charged and the starter should be in good condition. The compression is measured with both an open and a closed throttle valve. Both methods yield respective results, making it possible to define specific defects (see the Table below).
