| 1. At obvious deterioration in operation of the engine, or in case of interruptions in operation of cylinders at obviously serviceable fuel system and system of ignition, it is necessary to check a compression in cylinders. Results of check of a compression give the most reliable information about a condition of the engine. |
| 2. For obtaining exact results of check the engine has to be heated-up, the battery is completely charged, and spark plugs are turned out. Also the help of other person is required. |
| 3. Completely disconnect system of ignition for what disconnect the central high-voltage wire from an ignition distributor cover, connect it to weight on the block of cylinders. |
| 4. Insert the compression measuring instrument into an opening for a candle of the 1st cylinder. It is preferable to use the measuring instrument with a carving tip. |
| 5. Ask the assistant to squeeze out to the full a pedal of a butterfly valve and for several seconds to include a starter. After the first two turns of the crankshaft pressure in the measuring instrument has to increase up to maximum. Write down the maximum indication of the measuring instrument. |
| 6. Repeat measurements for other cylinders, write down indications of the measuring instrument. |
| 7. Indications of a compression in cylinders have to be almost identical. If distinction of a compression exceeds norm, then the engine is faulty. On the serviceable engine pressure has to increase quickly. Low pressure after the first piston stroke and slow increase at the subsequent steps of compression indicates wear of piston rings. If after the first piston stroke pressure low, and at the subsequent steps of compression does not increase, then leak in valves or not tightness of laying of a head of the block of cylinders is the reason (also cracks in a head of cylinders can be the reason). Decrease in a compression can be also caused by deposits of a deposit on heads of valves. |
| 8. If pressure in each of cylinders corresponds to the lower limit, or is lower than this limit, then through an opening for a candle enter into the cylinder a little oil for the engine (approximately full teaspoon), then repeat tests. |
| 9. If after introduction of oil to the cylinder the compression raised, then it is possible to draw an unambiguous conclusion that walls of cylinders and pistons are worn-out. If the compression increases slightly, or at all will not increase, then leak is caused progary valves, or violation of tightness of laying of a head of the block of cylinders. |
| 10. If the compression equally low only in two next cylinders, then is the most probable cause a laying burn-out between these cylinders. An additional sign is presence at oil of traces of cooling liquid. |
| 11. If the compression in one of cylinders is 20% lower than in the others and the engine not absolutely steadily idles, then wear of a cam of a cam-shaft of this cylinder is the reason. |
| 12. If value of a compression considerably exceeds norm, then the combustion chamber is covered with deposits of a deposit. In this case the head of cylinders should be removed and removed a deposit. |
| 13. Upon termination of measurements screw candles and put into place a high-voltage wire. |