One of the disadvantages of a diesel engine is difficult starting in winter. Usually the problem lies in poor quality fuel or faulty glow plugs. In the latter case, you can conduct an independent check without resorting to the services of a car service.
The function of the glow plug is to achieve the self-ignition temperature of the fuel, because compression alone will not start a cold engine. Structurally, the candle consists of a body, a core with a winding to which voltage is applied. If it is absent, then the candle does not heat up, the fuel does not ignite. You can check the operability of the fuel self-ignition system directly on the engine or by unscrewing the spark plugs.
Checking on the engine
The diesel engine can be started after the control lamp on the panel goes out. If the engine still does not start, then first check the voltage supply. To do this, connect any light bulb that will play the role of a control device to the "mass" and glow plug of the 4th cylinder. Turn on the ignition (but do not hold it in this position for more than 15 seconds). If the light is off, check the wiring. To check the performance of the candles, connect the test light to the "plus" of the battery, and the second contact to each candle separately, having previously removed the wires from them. The glow of the light bulb indicates the serviceability of the glow plug.
To check how the control system works, you need a voltmeter. It should be connected with one probe to the "ground", with the other - to the spark plug power bus. With the ignition on, for the first 10 seconds, the device will show the battery voltage (ambient temperature + 20 ° C), which will then gradually decrease by half. This value should be kept for about 10 minutes after starting the diesel engine. If the algorithm of the voltmeter readings is different, you need to inspect the parts of the control system.
Another factor affecting the quality of the candle is the strength of the consumed current. To find out this moment, you need an ammeter. Disconnect the supply wire from the candle and connect it to the positive pole of the ammeter. Connect its negative contact to the candle itself (positive contact). Turn on the ignition and look at the readings of the device. The main part of the pre-heating systems (4-cylinder engine) is designed for 48A (12A from each "candle"). If the ammeter shows a lower value, then one or more candles are faulty.
Checking inverted candles
Remove all plugs and install them on the common rail with the ends facing up. Connect the bodies of the turned-out elements with a thick wire and connect it to ground. With the ignition on, the winding on the core will warm up, the candles will light up. If one of them "burns" weaker than the others, then it must be replaced. You can simply inspect the candles - a burnt core indicates poor operation of the nozzle.
