At rather small fuel consumption the engine shows the best return of capacity only when piston rings provide good tightness. To define, valves and piston rings a manometer are how tight check a compression of separate cylinders. For the diesel engine the special adapter which is rolled instead of a nozzle in a head of the block of cylinders is also necessary. Recommended Volkswagen an adapter has number 1323/2A. Besides, you will need at least one sealing ring of thermal isolation as at check of a compression it is not necessary to use the established sealing rings.

The engine should be heated up to working temperature that piston rings provided the best tightness.

Fig. 450. Check of work of a glow plug by means of Volkswagen tester. Instead of a tester the manometer can be twisted in the specified place for a glow plug

The compression also can be measured in openings of candles of an incandescence. However you again will need the corresponding adapter (fig. 450) . Such adapter is used by Ford (GV2168).

Depending on what adapter will be used, act as follows.

Compression measurement in openings of candles of an incandescence

Take out the relay of the fuel pump from the block of safety locks (a place of the driver, space for feet). The relay is designated by R13.

Start the engine. After some time it will stop (intake of fuel) is blocked.

Fig. 391. Removal of a cover of the engine: 1 — a hose of forced air; 2 — a cap

Uncover the engine as it was already described at removal of a head of the block of cylinders (see fig. 391 ).

Disconnect the electric tire of candles of an incandescence from shtyrkovy conclusions.

Turn out glow plugs and wrap on their place the corresponding adapter. At first twist an adapter in the first cylinder.

Twist a manometer in an adapter.

Ask the assistant to turn the engine a starter. Scroll the engine until while the arrow of a manometer will not show the greatest value, i.e. the arrow will not rise any more.

Check in turn other cylinders.

In summary again establish all removed details. If the engine is not got, you for certain forgot to establish to the place of the relay of the fuel pump.

Compression measurement in openings of nozzles

Take out the relay as it was described, and let's to the engine work until it will not decay. It is also possible to disconnect a cable from the device of interruption of supply of fuel on TNVD and to isolate it. The cable in this case should be unbent aside.

Remove everything топливопроводы a high pressure from nozzles and remove nozzles (see the corresponding undressed). Put nozzles on a pure fabric or paper.

Fig. 451. The manometer 1 together with an adapter 2 is twisted in a nozzle opening

Twist an adapter with a sealing ring of thermal isolation in the first opening of a nozzle and connect it to a manometer (fig. 451) .

Ask the assistant to turn the engine a starter. Scroll the engine until while the arrow of a manometer will not show the greatest value, i.e. the arrow will not rise any more.

Check in turn other cylinders.

It is considered normal if value of a compression in one of cylinders does not fall below 80 % from the best result received at measurement of any cylinder. The low, unequal compression in different cylinders grows out of wear of piston rings that it is possible to determine by the raised consumption of oil also. At a good compression its size should be not less than 19,0 bar. The nominal size of a compression makes 25 — 30 bar. On the basis of comparison of the sizes received at measurement with nominal rate of a compression you easily can define degree of wear of the corresponding details.

If the received result of measurement approximately is equal to size of limit of wear, it is necessary to fill in a little engine oil in the engine through an opening of a spark plug and to repeat measurement. If the result appeared now better, it is possible to assume that the reason of a low compression are worn-out piston rings or the developed walls of the cylinder. If the received result remained approximately the same, the reason of a low compression most likely is one or a little badly working valves. Also there can be not tight a laying of a head of the block of cylinders. In any case it is necessary to remove a head of the block of cylinders and to carry out careful check for definition of a cause of defect.

Again remove a manometer and establish nozzles with rings of thermal protection as it is described in corresponding the section.