10.2. Check of system of prestarting heating of diesel engines

Check conditions
Tension of onboard network of the car has to be not lower than 11,5 Century.
The control system of the engine has to be serviceable.
Safety locks in a chain of giving of tension to glow plugs have to be serviceable.

Check
Switch off ignition.
Disconnect the electric socket from the sensor of temperature of cooling liquid. In this state the control system of the engine considers that the engine cold, and at inclusion of ignition will occur its preliminary warming up.
Disconnect electric sockets of wires from incandescence candles.
Connect the voltmeter a positive conclusion to a wire from incandescence candles, a negative conclusion to "weight". Include ignition and be convinced that tension to candles moves in the corresponding interval of time.
At the air temperature of 20 °C time intervals of giving of tension to glow plugs (the control lamp burns) have to make 5 pages. Time of burning of a control lamp increases at lower temperature and decreases at its increase. If tension moves to glow plugs, so the relay and an electrical wiring are serviceable.

Check of candles of an incandescence

Fig. 5.2-1. Glow plug of the diesel engine



Check each glow plug (fig. 5.2-1) for existence of mechanical damages. The burned or destroyed tips of a glow plug demonstrate bad dispersion of fuel a nozzle. In this case it is necessary to check nozzles and if necessary to replace.
If on glow plugs there are no mechanical damages, check their electric resistance which has to be less than 1 Ohm.
Operability of candles of an incandescence can be checked, giving on them tension of 12 Century. At the same time they have to heat up evenly for the required time interval. At the same time it is necessary to observe precautions:
1. To hold a glow plug a special clip or flat-nose pliers.
2. The electric power-supply circuit of a glow plug has to have the fuse.
3. After check the glow plug has to be cooled within several minutes.
The serviceable glow plug heats up to reddening of the lower part of an electrode during 5 pages. At longer heating or heating not in lower, and in a middle part the candle is faulty and is subject to replacement.