Attention! When carrying out checks of the ignition system, strictly observe the safety requirements. The order of operation of cylinders 1-5-3-6-2-4. Checking the voltage in the secondary winding of the ignition coils must be carried out using a test adapter «12.7.040» in the following order. Prepare fixtures «12.7.040», «12.7.041», «12.7.042», «12.7.043», «12.7.045», «12.7.046» And «12.7.050».
With adapter kit (adapters) The following types of checks can be carried out:
- checking the voltage in the secondary winding of the ignition coil;
- comparison of ignition coils of various manufacturers;
- identify defects in ignition coils;
- identify defects in spark plugs;
- identify faults in the fuel injection system.
Connect fixture «12.7.043» (connection cable) with fixtures «12.7.041», which are designed to be installed on ignition coils (pic. 3.36).
Take out the plugs (arrows, see fig. 3.32), remove the bolts and remove the oil filler cap, remove the protective cover of the ignition coils and replace the filler cap.
Install fixture «12.7.041» on the ignition coils and connect it to the tool «12.7.043» (pic. 3.37).
Connect DIS tester with RZV connection cable (static ignition distributor) to the last control adapter. Connect the trigger clamp of the DIS tester to the power wire of the ignition coil of the 1st cylinder.
Select on DIS modes «Measurement system» And «Preset measurements» and continue to act in accordance with the Manual for the DIS system. Analysis of waveforms in the secondary purpose of the ignition system.
Carrying out work according to the instructions for the DIS-tester system, analyze the shape of the received oscillograms (pic. 3.38), Where:
- 1. - the beginning of the maximum value of the breakdown voltage;
- 2. - height of the amplitude of the ignition voltage;
- 3. - the height of the voltage amplitude on the electrodes of the candle;
- 4 - the duration of the spark discharge;
- 5. - voltage curve on the electrodes of the candle;
- 6. - the beginning of the process of damping oscillations;
- 7. - damping of oscillations.
Note. Analyzing the oscillogram, it is necessary to take into account that the maximum value of the breakdown voltage (2) on the oscillogram is about 20-25% lower than its actual value.
The image of the processes in the secondary circuit of the engine ignition system at idle is shown on the oscillogram (pic. 3.39), the pulses are arranged in the order of operation of the cylinders «1—5—3—6—2—4».
Pay great attention to the uniformity of amplitudes in all cylinders, the permissible difference in values should not exceed 3000-4000 V. Image of processes in the secondary circuit of the engine ignition system in partial load mode (2000 min-1) shown on the oscillogram (pic. 3.40).
An analysis of the voltage curve at the spark plug electrodes and attenuation processes in idle mode is shown in Figure 3.41.
Pictures of possible malfunctions are well read when comparing the received oscillogram with the oscillogram of a working ignition system (pic. 3.42).
Normal spark duration (1) and the normal maximum value of the breakdown voltage (2) - the system is correct.
With a long duration of the spark discharge (1, fig. 3.43) and low amplitude of the maximum value of the breakdown voltage (2) - the system is working, but there is low compression in the engine cylinders.
Fluctuations in the duration of the spark discharge (1) indicates that the spark plug is dirty.
Constant but reduced spark duration (1, fig. 3.44) and high amplitude maximum breakdown voltage (2) indicate that there is damage to the high voltage wires.
If the high voltage wires are damaged, there may be no voltage curve at the spark plug electrodes at all. and the maximum value of the breakdown voltage can increase sharply.
Causes of too high ignition voltage can be:
- large gap between the electrodes of the spark plug;
- high compression in the engine cylinder;
- poor composition of the hot mixture;
- low temperature spark plug electrodes (cold candle);
- burnt spark plug electrodes;
- damaged high voltage wire.
Reasons for a too low secondary ignition voltage can be:
- small gap between the spark plug electrodes;
- low compression in the engine cylinder;
- enriched composition of the hot mixture;
- high temperature spark plug electrodes (hot candle);
- new spark plug electrodes.